PARASITOLOGY

Parasitology - study of the life cycle, morphology, pathogenecity, transmission, epidemiology, and control (diagnosis, treatment, and prevention) of parasites

History

17th century - mostly external parasites; few external parasites (large)

Francesco Redi - grandfather of Parasitology Demonstrated obligatory parenthood

in parasites Leeuwenhoek - described various kinds of

microscopic animals Linnaeus - described and classified the

helminths Rudolphi - gave scientific names to parasitic

worms Leuckart - demonstrated that insects serve

as intermediate hosts and vectors of parasites

First nematodes recorded in the Philippines by Schneider (German biologist)

Auchenatha corrolata - from the flying lemur (Cyanocephalus volans)Gnathostoma spinigerum - from the Philippine Civet cat (Paradoxorus philippinensis)

Trypanosoma evansi - first pathogenic protozoan parasite recorded in the Philippines in horses imported from India

Liborio Gomez - grandfather of Philippine Parasitology

Candido Africa (MD) and Marcos Tubangui (DVM) - fathers of parasitology

INTRODUCTION

3 Categories of Symbiosis:1. Mutualism - there is reciprocal advantage derived

from the union e.g. flagellate (Trichonympha campamula) and wood termite (Temopsis nevadensis). Flagellate digest wood particle for the termite while the latter gives protecti9on to the former.

2. Commensalisms - only one symbiont is benefited although the other suffers no harm e.g. Entamoeba coli and small intestine of man.

3. Parasitism - one symbiont receives the advantages to the detriment of the other e.g. Ascaris suis and pig

Parasite - an organism which for the purpose of procuring food and shelter, visits briefly or take up abode temporarily or permanently outside or inside the body of another organism where it usually does harm. The symbiont receiving the advantage is known as the parasite while the injured/harmed is the host.

KINDS OF PARASITES1. Optional occasional parasite - parasite that

briefly visits their host to obtain nourishment but not dependent upon them for either nourishment or shelter e.g. mosquitoes, sandflies

2. Obligate occasional parasites - those that do not permanently live upon their host but are dependent upon them for nourishment and to some extent for shelter e.g. fleas and ticks

3. Determinate transitory - parasitism is limited to a definite stage or stages in their life cycle, during which time, parasitism is obligate or continuous e.g. botflies, marble flies e.g. larva of dipteran flies which are deposited in dead or living tissue

4. Permanent parasite - parasitism extends from the time of hatching of the eggs to the time that the eggs are produced by the adult e.g. lice and mange mite

5. Fixed parasite - parasites that can not pass spontaneously from one host to the other e.g. helminthes

6. Erratic parasite - those that occur in organs far remoter from their normal location e.g. Ascaris suis in the fallopian tube, bile ducts of pigs; Stephanurus dentatus in the lungs

7. Monoxenous parasite - those that require only one host to complete their life cycle e.g. Ascaridia galli in chicken and Trichuris vulpis in dogs

8. Heteroxeneous parasite - those that require 2 or more hosts to complete their life cycle- If 2 or more hosts are required, that host wherein sexual maturity (eggs and oocysts are formed) is reached is known as the primary host, definitive or final host; the other host in which the parasite undergoes juvenile or larval development of asexual multiplication in the secondary or intermediate hoste.g. Plasmodium sp - final host - mosquito; man - intermediate host

Fasciola gigantica - final host - cattle, goat; snail - intermediate hostParagonimus westermani - final host – man; snail - 1st i.h.; crab - 2nd i.h)

9. Pseudoparasites - objects which are often mistaken for true parasite eggs and larvae because it resembles them e.g. pollen grain, fungal spores, yeast cells, plant spines

10. Ectoparasites or external parasites - parasites occurring on the surface of the body e.g. ticks, lice, mites.

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Infestation - condition produced by external parasites

11. Endoparasites or internal parasites - parasites found in the alimentary canal, blood, muscle, and other tissues of the host and the condition is term as infection e.g. roundworms, Plasmodia, coccidian

12. Facultative parasites - parasites that could exist both as free-living or parasitic e.g. larva of blowflies and flesh flies in tissues or wounds causing myiasis or in decomposing organic matter

13. Reservoir hosts - final hosts that harbor the infection but show no outward sign of infection. They serve as 'carriers', the organism multiply but not enough to cause a disease e.g. Trypanosoma evansi in carabaos

14. Transport or paratenic host - unnatural hosts in which parasites are accidentally lodged and transmission is though ingestion of paratenic host. Parasites remain in a dormant or suspended/inhibited stage (no development and multiplication) e.g. Toxocara eggs ingested by rats

or birds (paratenic hosts), when they are eaten by the susceptible host the encysted larva develop into the adult

15. Prepatent period - time of infection to the time eggs or larvae are demonstrated/produced in the feces to the time eggs disappear

16. Parasitic zoonoses - parasite transferable from animal to man and vice versa for parasites affecting man and animals e.g. Trichenella spiralis, Entamoeba histolytica

17. Parasitemia - presence of parasites in the blood18. Zooparasite - parasite that is highly specific for

animals e.g. Oxyuris equi19. Anthropoparasite - highly specific parasite for man

e.g. Enterobius vermicularis20. Anthropozooparasite - equally specific for man and

animals e.g. Trichinella spiralis21. Enzoonoses - man is essential for the life cycle of

the parasite e.g. Taenia solium; T. saginata22. Parazoonoses - unstable and changeable group;

man is just accidentally involved e.g. Ascaris suis

Transmission of Disease by Arthropods1. Mechanical / Non-cyclical transmission - when no

change in form or development occur in the arthropod body e.g T. evansi; amoeba; helminth ova

2. Biological transmission / Cyclical transmission - there is change in form or development of the parasite or orgaism in the body of the arthropod

>Types of Biological Transmission:1. Cyclopropagative transmission - the organism

undergoes cyclical changes or change in form as well as in number (multiplication) in the body of the arthropod e.g Plasmodia in mosquito

2. Cyclodevelopmental transmission - the organism undergoes cyclic development changing in form and size but no change in number, no multiplication in the body of the arthropod e.g. Dirofilaria immitis in the mosquito

3. Propagative transmission - the organism undergoes multiplication in the arthropod but there is no cyclical development or change in form and size e.g. Pasteurella pestis in the gut of the rat flea (Bubonic plague)

3. Transovarian transmission or hereditary transmission - transmission of infection is through the next generation of ticks. After the mature female tick ingests the parasite, the parasite invades the developing tick egg and when the young tick emerges, it carries with it the infective organism, then the mother dies after laying eggs e.g. Babesia in tick

4. Transtadial - organism is transmitted by the next developmental stage of ticks

5. Phoresy - transport of small parasite (lice and mites) by bigger parasite (flies, mosquitoes). Eggs of some flies are attached to abdomen of another fly, becomes hatched then deposited or transferred in another host e.g. Dermatobia hominis egg in the abdomen of mosquito; when Tabanus feeds, it could have lice attached to its leg and transfer it to another host

Factors that influence the degree of harm done by various parasites are as follows:1. Number of parasites present2. location of the parasite

3. nature of their food4. movement of parasites

5. Age of the host6. Virulence of the parasite

Effects of parasitic life on the parasites:1. Loss of certain sense organs - eye spots in some

external parasites (Melophagus ovinus)2. Loss of wings - bedbugs, lice3. Loss of alimentary canal – tapeworms4. Special development of some organs or adhesions5. Special development of organ of reproduction for

fecundity. Some flukes lay 250,000 to 2 million

eggs/day. Reproductive organs occupy 2/3 of the body cavity in general

6. Sexual dimorphism - female are larger than male7. Complex life cycle - need for the intermediate host to

increase chances of perpetuating species; multiplication in the i.h.

8. Greatly alters metabolism (some parasites can live anaerobically). Internal parasites that live

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anaerobically obtain energy by converting glycogen into fat. Internal parasite absorbs nutrients and vitamins from the host body.

9. Stay in the dormant/inhibited stage in the unnatural host (paratenic host) or even in the natural host (hypobiosis)

Pathogenic Effects of parasites

1. Absorb part of the digested nutrients, vitamins, and minerals

2. Suck blood or lymph3. Mechanical obstruction or pressure4. Growth of nodules5. Development of tumors6. Cause wounds7. Destruction of tissues8. Irritation and annoyance - interferes with feeding

which lead to loss of wt / meat / milk9. Secretion of toxins and other harmful substances

a. Anti-digestive enzymes

b. Digestive enzymes harmful to host tissuec. Anti-coagulatory and hemolytic enzymesd. Other secretions and excretions and body

fluids10. Transmits causal agents of some infectious diseases11. Reduce the resistance of the host to other infections12. Cause allergy (local or general)13. Serve as intermediate host and cyclic transmitter of

certain parasites14. Abortion, infertility, lowered productive and

reproductive performance15. Decreases feed conversion efficiency

Host specificity - parasite species associate only with one species of host, and if a parasite has more than one host, these hosts are usually closely related; only few parasites can live in a variety or a wide range of hosts

Organ specificity - each species of parasite has its predilection site in or on the host

ENTOMOLOGY

Entomology - the study of arthropods and allied insects

General Characteristics of Arthropods:1. bilaterally symmetrical

(appendages are always paired)2. body divided into head, thorax, and

abdomen3. joined with appendages

General structure and functionI. Integument - the body is covered by chitin; this

forms the typical body segment (sclerite) which are divided into tergum (dorsal), sternum (ventral), and pleuron (lateral)

II. Circulation - the hemocoele is a space full of blood which bathes all body organs; the system is composed of an enlarged dorsal blood vessel (heart), pericardium (encloses the heart), paired ostia (opening in the pericardial walls), and short arteries

III. Respiration - the arthropod may possess any or 2 of these short arteries

a. Gills (bronchiae) - found in larva, nymph, and adult aquatic species of various kinds

b. Trachea - fine elastic tubes in the chitinous lining which branches and ramifies among the internal organs

c. Lung book - found in spidersd. Gill book - found in crabse. Spiracle - smaller circular opening in

the exoskeleton

IV. Digestiona.Foregut or stomodeum - buccal cavity, pharynx,

proventriculus, gizzard; involved in ingestion, passage, and disintegration of food particles

b.Midgut or mesenteron - storage of food and enzyme secretion

c.Hindgut or proctodeum - absorption of food and expulsion of fecal materials

V. Excretiona. Paired nephridia – crustaceansb. Malpighian tubules – insectsc. Coxal glands

VI. Nervous systema. Supraesophageal center (brain)b. Ganlionated ventral nerve cord

VII. Reproductiona. Male - paired testes, vas deferens, paired seminal

vesicle, penile organb. Female - paired ovaries, oviduct, uterus, vagina,

spermatheca

Types of Development1. Direct / incomplete metamorphosis / hemimetabolous life cycle - 1 or 2 of the stages are missing with the

exception of the adult; hatched insect (nymph) is a miniature of the adult e.g. lice, bedbugs

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2. Indirect / Complete metamorphosis / holometabolous life cycle - characterized by having the 4 stages: egg, larva, pupa, adult; the hatched insect differs morphologically from parent. Each form of the insect after each ecdyses is known as the instar e.g. mosquitoes

Stages in the Life Cycle of an Arthropod1. egg - stage that undergoes a series of

segmentation2. larva - developing form after it has emerged from

the egg and before it is transformed into a pupa; it is the feeding stage of the parasite

3. pupa - the quiescent stage of metamorphosis that emerge from the larval stage

4. nymph - form that leaves the egg with similarity in morophology with that of the adult

5. adult - the reproductive stage of the parasite6. imago - the young adult

Types of larva:1. Polypod - larva with a marked head, a 3-

segmented thorax with legs, a 10-sefmented abdomen and pairs of abdominal legs or fleshy hooked legs e.g. caterpillars

2. oligopod - larva with a well-marked head, 3 pairs of thoracic legs, but no abdominal legs e.g. beetles

3. apodous - larva with no legs on the thorax and abdomen e.g. maggots

Types of Pupa:1. Free or exarate - the wings and legs are free from

the body and can be seen externally e.g. beetles2. Obtectate - pupa with legs and wings bound to

the body by molting fluid but still visible externally e.g. mosquitoes

3. Coarctate - last larval skin retained; this hardened skin (puparium) encloses the pupa, hence it cannot be seen externally

Types of Female1. Oviparous - lay undeveloped eggs e.g. housefly,

stable fly2. Ovoviviparous - lays larvated egg3. Viviparous / larviparous - lays fully-developed

larva e.g. flesh flies, tsetse flies, Oestrus ovis

4. Pupiparous - lays larva that immediately turns into pupa e.g. pigeon louse fly

5. Parthenogenetic - reproduce without males / fertilization e.g. silkworm, Strongyloides sp

General Classes of Arthropods1. Crustacea - main body divisions are

cephalothorax and abdomen; legs are found on thoracic and abdominal segments

2. Arachnida - adults with 4 pairs of legs; 2 pairs of mouthparts without antennae and wings

3. Pentastomida - adults without legs except 2 pairs of hooks near the mouth, larvae with 2 leg pairs

4. Insecta - largest group; adults with 3 pairs of legs; body divided into 3 main parts: head, thorax and abdomen

5. Myriapodaa. Diplopoda - elongated, cylindrical body,

terrestrial with numerous segments, each bearing 2 pairs of legs, with a pair of antennae

b. Chilopoda - long, narrow, and dorso-ventrally flattened; body with several segments each bearing a pair of jointed legs

CLASS INSECTAGeneral characteristics

1. Body divided into head, thorax, and abdomen2. 3 pairs of legs attached to the thorax and 2 pairs

of wings attached to the 2nd and 3rd thoracic segment

3. Veins - wings with hollow tubes which are useful for identification

4. The body is a rigid exoskeleton which is a deposition of chitin

Classification of mouthparts

1. mandibulate (chewing) - Orthoptera, Diptera2. haustellate (sucking) - Diptera, Hymenoptera3. piercing - Siphonaptera, Diptera

4. non-piercing / reduced / non-functional - Hymenoptera and certain Lepidoptera

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General Anatomy of Insects1. Nervous system - large ganglion (brain), thoracic

and abdominal ganglia, lateral nerve fibers2. Circulatory system -large dorsal tube (heart) and

valves; blood consists of watery fluid (serum or plasma) and white corpuscles which are colorless or greenish yellow

3. Respiratory system - tracheae, tracheoles, spiracles or stigmata

4. Digestive systema. Foregut or stomodeum - mouth, pharynx,

esophagus, crop and gizzard / proventriculus

b. Hindgut or proctodeum - colon, rectum, anus, malpighian tubules

c. Midgut or mesenteron - midintestine connects the stomodeum to the proctodeum

5. Reproductive systema. Male reproductive system - testes, vas

deferens, accessory organ, seminal vesicle, ejaculatory duct, penis or aedeagus

b. Female reproductive system - ovaries, oviduct, vagina, ovipositor, spermatheca (most insects)

Orders of Veterinary Importance under Class Insecta

1. Diptera - true flies2. Hymenoptera - bees, wasp3. Coleoptera – beetles

4. Siphonaptera – fleas5. Orthoptera – cockroaches6. Hemiptera – bugs

7. Phthiraptera - lice

ORDER DIPTERA (TRUE FLIES)

General Characteristics

1. well-developed anterior wings; posterior wing represented by haltere (organ of balance)

2. wings with hollow tubes called veins3. mouthparts adapted for sucking; haustellum (sucking

tube) formed by labrum and labium within which are

the mandible and maxilla; in some species, mandibles and maxilla are modified for piercing

4. complete metamorphosis

Suborder of Veterinary importance

1. Nematocera 2. Brachycera 3. Cyclorrhapha

SUBORDER: NEMATOCERAGeneral Characteristics:

1. antenna usually longer than head and thorax; more than 8 segments; wings without cross veins

2. larva and pupa are aquatic

3. larva with well-developed head and mandible; bite horizontally

4. obtectate pupa

Family: Culicidae - mosquitoes Ceratopogonidae - biting midges

Psychodidae - sandflies Simuliidae - black flies

SUBORDER: BRACHYCERA

General Characteristics1. antenna shorter than thorax; 3-8 segments2. arista usually absent; if present, located terminally3. maxillary palps held stiffly forward4. wings with cross veins

5. abdomen with 7 visible segments6. larva with incomplete retractile head7. obtectate pupa

Family: Tabanidae

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SUBORDER: CYCLORRHAPHA

1. antenna with 3 segments2. arista present, located dorsally3. small maxillary palps4. wings with limited cross veins

5. abdomen less than 7 visible segments6. larvae with vestigial head; apodous7. mouthpart has simple hooks used for tearing

debris8. coarctate pupa

Family: Muscidae Glossinidae Calliphoridae

Sarcophagidae Oestridae Cuterebridae

Gasterophilidae Hippoboscidae

SUBORDER: NEMATOCERA

CULICIDAE (MOSQUITOES)

Characteristics:1. slender insects2. larvae and pupa are both aquatic and active3. scales are present on the head, thorax, abdomen,

legs, and wings4. antenna plumose in male and pilose in female5. head is spherical and the mouthparts form the long,

slender proboscis6. only female are blood sucking; male subsist on

juices of flowers and fruits

7. proboscis consists of the mandibles and maxillae which are the piercing instruments enclosed in the upper lip called labrum epipharynx and the lower lip, the labium; it also encloses the hypopharynx; the tip of the labium is modified to form the labellum; mandibles are absent in the male mosquito

Genera of Veterinary and Medical Importance:1. Anopheles (A. maculippennis)2. Culex (C. pipiens)3. Aedes (A. aegypti)

4. Mansonia sp.5. Theobaldia sp.6. Orthopodomyia sp.

7. Myzorhynchus sp.8. Taeniorhynchus sp.9. Luzonia sp.

TABLE 1: Differential characteristics of Anopheles, Aedes and Culex mosquitoesAnopheles sp. Aedes sp. Culex sp.

Egg Laid singly with lateral floats Laid singly without lateral floats

Laid inmass (egg raft)

Larvae Lies parallel to the water surface; no siphon tube

Hangs diagonally from the water surface

Hangs diagonally from the water surface

Pupa Short and stout breathing trumpet Long and narrow breathing trumpet

Long and narrow breathing trumpet

Adult palpi Female palp is as long as the proboscis

Palp of female is shorter than the proboscis

Palp of female is shorter than the proboscis

Resting position

Diagonal against the landing surface Parallel to the landing surface

Parallel to the landing surface

Feeding Crepuscular Diurnal Nocturnal

Life cycle:

Eggs laid on the surface of water or on floating vegetable matter eggs hatch in 16-24 hours into larvae or wrigglers larvae feed on algae but others are carnivorous; they breathe through a siphon tube larva molts 4 times in about 7 days becomes an obtectate pupa or thumbler; they breathe through a trumpet; it does not feed imago emerges after 2-3 days then sucks blood after 24 hours lay eggs after about a week.

Life span of mosquito - 15 to 20 days under favorable conditions; longer period if otherwise

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Life cycle of anopheles mosquito

Feeding period of mosquitoes:A. Nocturnal - active at night time

or in the dark e.g. CulexB. Diurnal - active at day time e.g.

AedesC. Crepuscular - active at

twilight e.g. Anopheles

Pathonegenic Effects of Mosquito

1. annoyance and blood loss2. decreased milk and meat production3. serve as intermediate host of several parasites:

a) filarial parasite Wucheraria bancrofti - Culex,

Aedes, Anopheles (elephantiasis) Dirofilaria immitis - Culex,

Anopheles (heartworm)b) Malaria parasite (Plasmodia)

Plasmodium juxtanucleare and P. gallinaceum (avian malaria) - Culex, Aedes

Simian malaria - Aedes4. serve as mechanical carriers of pathogenic

bacterial and viral diseasesa. fowl pox - Culex, Aedesb. viral encephalitis - Culex pipiensc. yellow fever - Aedes aegyptid. H-fever - Aedes aegyptie. Dengue - Aedes aegyptif. Tularemia - Anopheles, Aedesg. Fowl cholera - Culex

Control of mosquitoes1. Physical means

a. Destruction of breeding places Drain stagnant pools Dispose empty cans / containers Clear breeding places of

vegetationb. Screen stables, barns, and animal houses

2. Chemical meansa. Spray breeding places with appropriate

insecticides

1.0% dieldrin 2.0% lindane 0.5% gm/ha malathion

b. cover pond surface with petroleum or kerosene

c. saturate sawdust with 2.0% DDT in diesel oil and scatter upstream

d. use of mosquito repellents

Biological controla. Use of predators like fish and ducks to control

larvae and pupab. Use of bacteria (Bacillus thuringiensis) to kill

larva and pupa

c. Use of protozoan parasites (Microsporidia sp)d. Sterile male techniquee. Use of chemical sterilant

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CERATOPOGONIDAE (MIDGES)

Genus: Culicoides1. very small; 1-3 mm long; can pass through

mosquito screens2. thorax humped over the head3. wings oval in shape; usually spotted; no scales but

hairs

4. long antenna (14 segments); plumose in male, pilose in female

5. short proboscis; only female are blood sucking

Species:Culicoides arakawaeC. damnosus

C. palawanensisC. pungens

C. baisasae

Life cycle:Eggs laid in objects partly submerged in water hatch into larva in a few days; worm-like with 3 thoracic and 9

abdominal segments; feeds on tiny aquatic nematodes obtectate pupa emerges after 1-2 weeks; covered with spines and tubercles adult develops in few days

Importance:1. bites cause itching and swelling2. causes allergic dermatitis in horses (Queensland

itch) - Culicoides robersi3. serve as i.h. of filarial worms in man:

Dipetalonema and Manzonella spp; in animals: Onchocerca in cattle and horses

4. Intermediate host of Leucocytozoon caulleryi5. transmits Blue tongue in sheep6. transmits fowl pox virus7. Nocturnal

Control:1. screen treated with insecticide to repel entry2. application of 5% dieldrin in breeding places

3. spray with adulticide (chlordane, lindane, dichlorvos, endrin, parathion)

SIMULIIDAE (BLACKFLIES, BUFFALO GNATS)

Genus: Simulium1. small; 1-4 mm long2. stout; short legs; thorax humped over the head

(humped back appeatance)

3. short piercing proboscis; only females are blood-sucking

4. broad wigs; not spotted; no scales; not hairy5. holoptic eyes in male; dichoptic in female

Species:Simulium indicumS. venustrum

S. baltazaraeS. baisasae

S. philippinensis

Life cycle:Eggs laid on objects partly submerged in water in running streams hatch into larvae in 4-12 days depending on

temperature; larvae are carnivorous develops into pupa after 6 molts adults emerge after 5-6 days which are active early in the morning and in the morning and in early evening

Life cycle of Blackfly

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Importance:1. causes painful bites and gives rise to vesicles and

wart-like lesions2. swarms cause animal to stampede3. causes anemia in poultry in severe infestation4. low milk and meat yield5. serve as i.h. of Leucocytozoon anatis / simondi in

ducks and L. smithi in turkeys

as well as Haemoproteus nettionis in ducks and geese

6. serve as i.h. of filarial nematodes - Onchocerca gutturosa - cattle, O. volvulus – man

7. inhalation of flies may cause foreign body pneumonia

Control:

1. medicated screen / clothing2. spray with 0.5% lindane

3. apply 0-1-0.3 ppm DDT to streams in 2 cycles, each cycle lasting 10 days as larvicide

PSYCHODIIDAE (SANDFLIES, OWL MIDGES)

Genus: Phlebotomus

1. small, slender flies, up to 1.5 mm long2. wing and body are hairy3. legs long4. long, slender, and hairy antennae; with 16

segments; often with beaded appearance5. recurved palpi; hairy6. piercing mouthparts; only females are blood sucking

7. nocturnal feeding habit

Note: Lewis classified these flies into 2 families: Phlebotomidae (sandflies) - blood

sucking Psychodiidae (moth flies) - not blood

sucking

Species:Phlebotomus philippinensisP. nicnicP. mangyanisP. lagunensis

Life cycle:

Eggs laid in batches of 40-60 in moist dark places between stones, loose soil, rock, crevices, etc. larvae molt 4x pupae adult (entire life cycle takes 6 weeks)

Importance:

1. P. papatasi, P. sergenti, and P. major serve as i.h. ofa. Leishmania tropica - cutaneous

leishmaniasisb. Leishmania brazilensis - mucocutaneous

leishmaniasisc. Leishmania donovanii - visceral

leishmniasis or Kala-azar

2. P. mongolensis and P. verrucarum serve as transmitter of Bartonella bacilliformis, the

causative organism of Carrion's disease (Oroya fever)3. Transmit virus of 'sandfly fever' where a transmission is possible

Control:

1. removal of dense vegetation2. spray walls with insecticides

3. treatment of breeding places

SUBORDER: BRACHYCERA

TABANIDAE (HORSEFLIES OR BREEZE FLIES)

Genera: Tabanus Chrysops

PangoniaHybometra

SilviusHaematopota

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General characteristics:1. large robust flies with powerful wings and large

eyes2. eyes holoptic inmales, dichoptic in females3. antenna with 2 short basal segments, the 3rd

segment being large and usually ringed or annulated

4. proboscis is relatively short in Tabanus and Hematopota, longer in Chrysops and very long in Pangonia which projects forward

5. eyes are metallic in color6. wings of Chrysops has a dark band and is

divergent at rest; Hematopota has mottled wings; Tabanus has a clear wing which is horizontal at rest

Habits of Adults:1. most active on hot sunny days2. attack singly, chiefly large animals like cattle,

carabaos, buffaloes, and horses3. feeds mainly of the underside of the abdomen,

around the navel, on the legs, neck, and withers

4. intermittent feeding habit (bite in a number of ties in different places or different animals before they are replete with blood)

Life cycle:Eggs laid in batches of 300-600 in stones or leaves overhanging body of water or marshy places larva drops to

the ground after about a week; larva is maggot-like, aquatic, and carnivorous larva undergoes 6 ecdyses for 2-3 months pupate in the drier ground for 2-3 weeks adult (cycle completed in 4-5 months)

Life cycle of Horsefly

Pathogenic effects:

1. bites are painful and irritating that animals become restless

2. acts as mechanical carrier of diseasesa. bacterial diseases - anthrax, tularemiab. viral diseases - equine infectious anemiac. protozoan disease:

surra caused by Trypanosoma evansi

mal de cadera caused by T. equinum

nagana or sleeping sickness caused by T.brucei and T. vivax

anaplasmosis caused by Anaplasma marginale et centrale

3. serve as i.h. of filarial nematodesa. Loa loa – Chrysopsb. Elacophora schneideri - Hybometra and

Tabanus4. serve as i.h. of Trypanosoma theileri of cattle and

carabaos

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Control1. use of fly trap or net2. catching manually using animals as baits

3. spray with mixture of 1% pyrethrin and 10% piperonyl butoxide at the rate of 1 L/large animal

SUBORDER: CYCLORRHAPHA

MUSCIDAEGenera:

MuscaFannia

StomoxysHaematobia / Lyperosia

Musca domestica "common housefly" - human and animal houses and buildingsMusca autumnalis "face fly" - nostrils and eyes of cattle and horseMusca sorbens - markets and housesM. conducens - animal houses

Characters:1. not blood-sucking, non-biting, indoor flies2. 6-7 mm long3. arista bilaterally plumose up to the tip, thorax4. thorax and abdomen with stripes on the dorsum5. mouthparts are lapping type; fleshy, expanded labella and covered by pseudotrachea adapted for imbibing

liquid food

Life Cycle:Eggs are laid in batches of 100-150 at a time (about 1,000 eggs) in animal manure or any fermenting or decaying

organic matter eggs hatch in 20-24 hours larva persists for 4-8 days then pupate pupal stage lasts 4-5 days or longer young adult emerges from the puparium by means of the ptilinium fertilization and oviposition takes a few days after emergence of the fly from the pupariumNote: It has been estimated that a pair of Musca can be a progenitor of 191,000,000,000,000,000,000 in 6 months with 100% survival

Habits of houseflies and their role in disease transmission:1. adults feed on human food, blood and serum from meat, or from blood that oozes out from other insect bites,

mucus, sputum, excretions from sores, wounds, etc2. female deposit eggs on human and animal manure; they go back and forth between food and feces which is ideal

for disease transmission11

3. after a full meal, part of the ingested food is regurgirated back to the outside, this material is called "vomit drop" or "vomit spot"

4. fly specks or fecal deposits - houseflies also deposit feces or defecate on food5. labella are fleshly and wrinkled, the presence of pseudotrache make them very efficient as disease transmitters6. hairy legs, body, foot pads - efficient disease transmitter7. M. autumnalis - commonly found around the nostrils and eyes of cattle, horses and other animals including man

especially during summer

Disease transmitted:1. Mechanically transmitted

a. ViralCholeraEl torPoliomyelitis

b. Bacterial Salmonella --- typhoid Vibrio – dysentery Bacillus anthracis – anthrax Moraxella bovis - Infectious Bovine Keratitis (Pink eye) Mycobacterium sp. – Tuberculosis

c. Parasites1. amebiosis – Entamoba histolytica2. coccidiosis – Eimeria and Isospora3. helminths – Ascaris, Trichuris, Enterobius

2. Serves as intermediate host of the ff:a. Raillietina spb. Habronema muscae - equine stomach wormc. Thelazia rhodesii (cattle eye worm) - by Musca autumnalis

Control1. Larvae

a. Destruction of breeding places Spreading manure thinly on pasture Spraying manure with larvicide like Borax powder over a heap of manure

c. Inhibit larval development - Larvadex in feedd. Frequent removal of manure

2. adulta. mix molasses (sugar) with insecticides (diazinon, dieldrin, parathion, neguvon) and sawdustb. spray with insecticides (baygon, malathion, neguvon)c. backrubbers with either 2% malathion dust, dichlorvos, and 5% metoxychlord. insecticidal dust bags

3. proper garbage disposal4. efficient sewage disposal5. screening of houses

Relatives of houseflies1. Fannia canicularis - lesser housefly2. Fannia scalaris "little housefly" - may cause "urogenital myiasis"; smaller than Musca; larvae with feathered

protuberances; arista is bare3. Muscina stabulans - may cause "intestinal myiasis"; larger and more robust than the housefly; common in stables4. Morrelia hortorum "sweat fly" - adults attracted to sweat and mucus

Stomoxys calcitrans "stablefly"1. proboscis is sucking type, directed horizontally forward2. arista plumose only dorsally3. thorax has 4 longitudinal stripes of which the 2 lateral are broken4. the abdominal segment which is shorter and broader is provided with 3 dark spots5. outdoor flies and both male and female are blood sucker

Life cycle:Female lays 25-50 eggs at a time (total of 800) in decaying vegetable matter after at least 3 blood meals 1eggs

hatch in 3 days larval stage lasts for 12 days pupate on drier ground for 6-9 days oviposition begins 9 days after emergence

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Life cycle completes in 30 days; life span is about 72 days

The Life Of Stomoxys Calcitrans

Pathogenic effects:1. cause annoyance2. serves as mechanical transmitter of :

a. protozoa T. evansi T. equinum T. brucei T. vivax T. gambiense T. rhodesiense

b. Bacteria B. anthracis Hemorrhagic septicemia (P. multocida) Equine infectious anemia

3. Serve as i.h. of equine stomach worm (Habronema spp)

Control:

1. frequent removal of manure and fermenting materials2. spray manure thinly on the pasture3. spray animal houses and animal with insecticides like DDT in kerosene4. backrubbers

Hematobia (Lyperosia or Siphona)

Hematobia exigua - buffalo fly

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H. irritans - hornfly

1. smaller than S. calcitrans; about 4 mm in length2. male and female are blood suckers3. palpi as long as proboscis4. thorax with 2 dark stripes5. hovers around face and body of carabaos, cattle, and buffalo6. rarely leave the host except for a brief flight when disturbed7. infestation reaches 1000-4000/animal to as high as 10,000 to 20,000/animal

Life cycle:Eggs laid in fresh Carabao or cattle manure hatch in 24 hours larval stage lasts for 4 days pupate for 5-10

days adult

Life cycle of Hornfly

Effects on the hosts:1. interferes during grazing periods2. animal develop sores and wounds resulting to myiasis3. fly specking - animals constantly shake their head to drive away flies4. cause blood loss, low milk and meat yield by 10-20%5. transmits mechanically surra, anthrax, hemorrhiagic septicemia.6. serve as i.h. of Habronema sp and Stephanofilaria stilesi

Control:1. backrubbers impregnated with 5% rotenone, 5% methoxychlor dust, 2% malathion

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dust2. regular insect spray

GLOSSINIDAE (TSETSE FLIES)

Glossina morsitansG. palpalis, G. longipalpalis, G. brevipalpalisG. tachinoides

1. larger than the houseflies, narrow-bodied, yellowish to dark brown2. common in Africa3. both sexes are blood suckers4. arista bears dorsal branching hairs5. proboscis is held horizontally and ensheathed in long palpi which is as long as the proboscis

Life cycleLarviparous female lays on fully-grown larva at a time pupates upon liberation in sandy soil with humus around

tree trunk, crack or crevices under shaded areas pupal period is 35 daysNote: Gestation period is 10 days; one female may produce 8-10 larvae; one act of mating renders a female fertile

for life; the larvae within the uterus is attached to a "teat" from which "milk is obtained

Habits:1. adult flies subsist on blood of warm blooded animals2. fly feeds every 3 days; active in forenoon and afternoon; some spp. Are noctural (G. brevipalpalis)3. rest on shady places

Effects on the host1. serve as i.h. of Trypanosoma brucei, T. congolense, and T, vivax which cause "Nagana" in animals and T.

gambiense and T. rhodesiense which cause "sleeping sickness" in man

Control:1. Previous strategies

Large scale killing of game animals which are reservoir hosts Clearing large areas of bush to destroy the fly habitat

2. Current strategies Insecticides sprayed from the ground or by aircraft Non-residual or residual insecticide Trapping - use of dark cloth impregnated with insecticide Catching with hand nets Fly screens Biological control - release of sterile males

MYIASIS FLIES

Myiasis flies - dipterous insects whose larvae invade tissues or organs of man and animals causing a condition known as myiasis. The adults do not suck blood

Myiasis may be grouped according to their ovispositioning and larvipositioning habits:

1. Accidental myiasis - eggs or larvae are deposited in manure or decaying organic matter, garbage, carcasses, and myiasis is usually acquired accidentally by ingestion of eggs or larvae with contaminated feed or water. Eggs may be deposited around the anus or vulva and larvae, and upon hatching, migrate to the rectum or intestine and vagina respectively.

Species InvolvedBlue Bottle Flies - Calliphora sp.Green Bottle Flies - Lucilia sp.Fleshflies - Sarcophaga sp.Houseflies sp. - Musca sp

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2. Specific or obligate myiasis - eggs or larvae are deposited in or near living tissues / organs and larvae inevitably become parasitic

a. Screw worm flies Callitroga sp Chrysomyia sp.

b. Bot flies Gasterophilus sp

c. Warble flies Hypoderma sp

3. Semi-obligate myiasis - eggs and larvae are deposited in decaying organic matter and less frequently in diseased tissues and neglected wounds

a. Flesh flies - Sarcophaga spb. Green Bottle Flies - Lucilia spc. Blue Bottle Flies - Calliphora spd. Black Bottle Flies - Phormia sp

Myiasis may also be classified according to organ affected: Cutaneous - skin Ocular - eyes Aural - ears Gastric - stomach Intestinal - intestine Vaginal, nasal, scrotal, rectal, etc.

Myiasis belong to four important families:

CalliphoridaeSacrophagidaeOestridaeCuterebridae

Identification key for agents of wound myiasis:

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CALLIPHORIDAE

Genera: Calliphora - blue bottle flies Lucilia - green bottle flies / copper bottle flies Phormia - black blow fly

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Chrysomyia - screw worm fly Callitroga - screw worm fly Cordylobia - skin maggot fly Booponus - foot maggot fly

Calliphora vomitoriaC. erythrocephala

Stout with metallic blue color Measures about 12 mm; with red eyes Squama with short and long hairs

Lucilia cuprina / Caesar - affects sheep in AustraliaL. sericata - affects sheep in the US

Stout flies with metallic coppery green Squama with short hairs only Eyes are brownish red Measures about 8-10 mm

Phormia reginaP. terrae-novae

Black with metallic blue-green sheenNote: maggots of these 3 genera produce 'blowfly strike' in sheep

Life cycle of calliphorine flies in general:

eggs are laid in cluster in batches of 50-150 (around 3,000-5,000 eggs are laid in a lifetime) eggs hatch in 8 hrs to 3 days giving rise to larvae which are segmented, wormlike, mobile, and apodous larvae molt twice and becomes a fully-grown maggot in 2-19 days prepupal period of 2-7 days mature larvae leave the host or carcass to pupate on the ground pupa persist for 3-7 days adultLife cycle is complete in 2-5 weeksLife span of adult - 1 month or longer; 9-10 generation may be completed in a year

Pathogenesis:

1. wounds on the skin attract blowflies2. eggs are laid on the wool3. larvae form deep tunnels in tissues; maggots secrete proteolytic enzymes which digest and liquefy tissues of the

host then feed on them4. foul smell attracts other flies to lay their eggs5. larval movements cause irritation; animal does not feed properly resulting in emaciation and weakness and

consequent reduction in meat and milk yield6. burrowing of larvae into the skin may be complicated by secondary bacterial infection7. animals may die of toxemia or septicemia8. the value of the fleece becomes reduced

Treatment

1. clip wool and surgically remove the larvae2. use of low concentration dressing compounds3. dip or spray with insecticides

Callitroga hominivorax - primary screw worm flyC. macellaria - secondary screw worm fly

bluish green color with 3 longitudinal stripes on thorax eggs are laid at the edge of the wound or on the carcass adult is formed after 3-7 days

Effects on the host:

Rainy weather predisposes the animal to screw worm infection; they penetrate into the tissues, which they liquefy and extend the lesions considerably. The effect on the animal is more on the production aspect, as the animal becomes weak and restless.

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Treatment:

1. thorough cleaning of wounds and dressing it with appropriate antiseptics2. destroy larvae

Chryzomyia bezziania - "bluish green fly" most important myiasis fly in the Philippines particularly in Negros and Panay islands maggots of Callitroga and Chryzomia are known as screw worms attack man and animals

Life cycle:

Eggs laid in clusters of 150-300 at the edges of wound or sore eggs hatch in 10-12 hours and mature in 3-6 days drops to the ground and pupate for 3-7 days but may reach up to 2 months adult

Pathogenic effects:

1. maggots penetrate and liquefy tissues2. lesions attract more flies3. severe cases may cause death4. myiasis of the navel may lead to peritonitis, septicemia, and death

Treatment:

1. dress wound with 0.3% dieldrin or 0.5% BHC2. dipping or spraying with 5.0% coumaphos, 0.25% diazinon3. 3% of lindane in gel base4. Myiasis smear / paste #1

chloroform - 40 ml (larvicidal) tincture of iodine - 25 ml (stimulate tissue growth) pine tar - 28 ml (fly repellent) charcoal powder enough to make a pasty consistency (gives thickness to smear)Apply two times a week

Myiasis paste #2 Charcoal powder - 95 parts Coumaphos powder - 5 parts Pine tar - q.s. [aste

Cordylobia anthropophaga - tumbu fly or skin maggot fly Occurs in tropical Africa Measures 9.5 mm and light brown in color

Life cycle: Eggs laid on sleeping places of man and other animals with perspiration odor larvae produced after 2-4 days

penetrate intact skin and produce painful swellings pupa is produced after 8-15 days adult develops after 3-4 weeks

Pathogenic effects: The larva is situated ion a swelling which is about 1 cm in diameter, painful, and has a small, central opening.

Treatment: Press out larva and apply a disinfectant

Booponus intonsus - foot maggot fly The same size as the housefly but light yellow in color Common during the dry season in Laguna, Quezon, Leyte, and Mindanao Attack ruminants

Life cycle:

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Eggs are laid on the hairs along the coronet and the posterior part of the hoof eggs hatch into larvae in 3-5 days then penetrate and produce wounds pupa is produced after 2-3 weeks adult develops 10-12 days

Pathogenic effects1. lameness due to pain in the foot parts2. secondary bacterial infection (Bacteriodes nodusus) particularly Foot rot complicates the condition

Treatment:1. apply grease mixed with 0.3% dieldrin/diazinon2. soak large piece of cotton in chloroform or kerosene and pack affected foot; remove maggots with forceps then

paint with pine tar or myiasis paste

SARCOPHAGIDAE (FLESH FLIES)

Sarcophaga hemorrhoidalisS. fusicauda

light or dark grey in color thorax with 3 longitudinal stripes abdomen with dark checkered markings larviparous

Life cycle: Larvae deposited in fresh or decomposing meat, wound, sores, and abscesses; larva becomes a pupa in 6 days à

the pupa transforms into imago after 12-24 days

Wohlfartia magnifica - deposit larva in cutaneous lesions or sores, nasal, and aural cavities, eyes and vaginaWohlfartia vigil - deposit larvae on intact skin

GASTEROPHILIDAE (HORSE BOT FLIES)

Criteria Reference of the Different Gasterophilus sp.Site of egg deposition

Routes of larval penetration

Larval predilection site

Gasterophilus intestinalis

Hairs all over the body preferably on forelegs, around fetlock, and underside of knees

Tongue mucosa Cardiac portion of stomach

Gasterophilus nasalis Hairs in the intermandibular space (throat)

Mucosa between molar teeth

Pylorum an duodenum

G. hemorrhoidalis Hairs of lips and cheeks

Tongue mucosa Stomach and rectum

G. pecorum Hooves and inanimate objects

Cheek mucosa Stomach and rectum

G. inermis Hairs of lips and cheeks

Cheek mucosa Pharynx, esophagus, and stomach

Life cycle: Eggs hatch after 5-10 days (eggs of G. intestinalis and G. pecorum have to be licked or rubbed by the host to

hatch while others hatch spontaneously larva migrate in the mouth mucosa and wander as far as the pharynx for 3-4 weeks fully grown larvae pass down the stomach and lodge in predilection sites larvae remain in the host for 10-12 months detach and pass out in the feces to pupate in the ground (those of G. hemorrhoidales and G. pecorum reattach for a few days in the rectum before leaving the host) pupal period lasts for 3-5 weeks before the adult is formed

Pathogenesis:1. oviposition pattern cause annoyance2. stomatitis with tongue ulceration3. cluster of maggots around pylorus mechanically interfere with action of sphincter and food passage4. spines of the larvae may cause ulceration in the stomach which may be dramatic in appearance but have obscure

pathogenic significance20

5. abscess formation, rupture of stomach, peritonitis6. accidental larval infection in man is limited to skin "creeping eruptions"

Diagnosis:1. Examination of sites at which eggs are deposited2. direct inspection of the pharynx may reveal the larvae3. larva in the stomach and rectum may be seen at necropsy

Treatment:1. piperazine and carbon disulfide complex - 20-40 grams/500 lbs via stomach tube2. dichlorvos - 14-15 mg/lb given in feed3. neguvon - 40mg/kg/wt (98& trichlorfon)

OESTRIDAEGenera:

OestrusHypodermaRhinoestrus

Oestrus ovis 'sheep nasal fly' 'nasal bots' 'sheep Nose fly' 'head maggot fly'

Lifecycle:Female infect sheep by squirting a jet of fluid with larvae during flight (up to 25 at a time/ 60 in an hour)→larvae

are deposited in nasal cavites and adjacent sinuses, sometimes in the eyes, nostrils, and lips of man→ larvae migrate to nasal passages feeding on mucus whose secretion is stimulated by their movements (L1-L2)→frontal sinus (L3)→lavae may die and calcify in this sites or larvae mature in 8-10 months then crawl out and drop to the ground to pupate →adult emerges after 3-6 weeks

Pathogenic effects:1. larviposition causes annoyance which may cause the animal to panic, stamp their feet, bunch together and press

their bodies together against the ground; this interruptions may cause decrease in the production.2. larvae irritate the mucosa which may cause viscid mucus nasal discharge, sneezing and rubbing of nose to fixed

objects.3. causes “false gid” – the bones of the skull may erode and cause injury to the brain producing nervous signs such

as high stepping gait, incoordination and paralysis.

Treatment:1. induce sneezing by sprinkling snuff and pepper into the nostrils2. administer 10 parts neguvon and 1 part coumaphos per os3. apply 3% cresol-soap solution to the nostrils4. trephination – create an opening to the skull

Hypoderma - “warble flies” ”ox bot flies” ”heel flies”Hypoderma bovis “northern cattle grub” – affects cattle; most important speciesH. lineatum “common cattle grub” – affects cattleH. ageratum – sheep and goats (India)H. crossi – sheep and goatsH. diana – deer (Europe)- adults are hairy; 13-15cm long- light yellow color as honey bees- mouthparts are redumentary and do not feed- most active during sunny days- adults live for an average of 1 week- female may lay 400-600 eggs in the course of her life

Life cycle:

Eggs are laid singly at hairs above the hock (H. bovis) or in rows of 6 or more at hairs below the hock (H. Lineatum); 100 or more eggs are laid in a week→eggs hatch and larvae crawl down the hair and penetrate hair follicle→ migrate towards the diaphragm via the SQ tissue up the leg (L1) aided by mouth hooks and secreted proteolytic enzymes→ submucosa of esophagus (H. lineatum) or epidural fat of spinal canal (H. bovis) – L2 for 2 to 5 months→ reaches the SQ tissue of the back (L3) and form swellings (warbles) that measures 3cm→ L3 creates a perforation and

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apply their spiracles to the aperture for breathing purposes→larvae molt twice and mature in 30 days then fall to the ground to pupate(4-5weeks) →adultThe complete life cycle takes about 1 year

Pathogenic effects:

1. economic losses due to fly attacka. “Gadding” – animals panic when attacked by buzzing flies especially H. bovis that lay its egg singly

therefore has to repeatedly attack the animal. The animal tends to run away aimlessly and injure themselves on fences or may die when they fall off in water over heights

b. interrupted feeding – low milk and meat yield2. downgrading and condemnation of hides3. carcass depreciation – the flesh under the skin infested with L3 may be damaged producing the characteristic

greenish gelatinous tissue which has to be trimmed “Butcher Jelly”4. if the larvae dies in the spinal cord, the highly toxic proteolytic enzymes may cause paraplegia in the esophageal

wall, it may cause bloat due to esophageal stricture5. aberrant migration due to other organs may cause anaphylactic reactions or signs relative to the organ6. escape of the larvae leaves an open wound which attracts myiasis flies.

Clinical signs:

1. usually, there is no appreciable manifestation until the larvae appear along the back when the swelling can be felt and seen; larvae lies in a cyst containing yellow purulent fluid

2. poor growth is observed in severe cases3. decreased milk yield

Treatment:

1. Removal of larvae (mechanical) – ineffective when larvae are immature because its rupture may lead to inflammation, abscess formation or anaphylaxis

2. application of larvicide – organophosphate compounds and ivermectin

Rhinoestrus purpurensis “gadfly”- larvae satges are obligatory parasites of the nasal sinuses and larynx of horses- cause opthalmomyiasis of man

CUTEREBRIDAE

Genera:CuterebraDermatobia

Cuterebra emasculator “rodent bot fly”- occurs under the ski of rodents, rabbits, dogs, cats and man- present in north America

Life cycle:Eggs are deposited I burrows of rodents; each females lays 2000 eggs→ eggs hatch and wait for host→

penetrate skin of nose and mouth and migrate to various SQ locations (frequently parasitizes the scrotum destroying the testes (parasitic castration)→ larvae mature in 30 days the pupate on the ground.

Dermatobia hominis “human bot fly” “tropical warble fly” adult flies do not feed- occurs in central and north America- man are infected by association with domestic animals

Life cycle:

Adult females rest on leaves, captures a mosquito or other blood sucking fly→ glues a batch of eggs to the abdomen of the capive fly in 7 days (L1 develops within the egss)→ eggs hatch when insect land on warm-blooded

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animal when the latter sucks blood→ larvae penetrate skin using the skin puncture made by insect and migrate to the SQ tissue (larvae grows and produce a swelling under the skin)→ pupate on the ground→adults develops after 5-10 weeks

Pathogenic effects:1. cause “Uva” swellings in the various body parts which may suppurate and cause severe pain2. attracts myiasis flies

Treatment:1. surgical or mechanical removal2. ivermectin or topical trichlorfon

HIPPOBOSCIDAE (LOUSEFLIES OR KEDS)

General characteristics: Pupiparous (female may lay larvae ready to pupate) Pupa is roughly rounded and smooth like a brownish bean seed With strong claws by means of which the parasite clings to the hairs or feathers of the host With piercing blood sucking mouthparts in both sexes Maybe permanent parasites

Genera:Hippobosca “forest flies”PseudolynchiaLepopthenaMelophagus

Hippobosca equina “horse lousefly” “horse ked” – attacks horse and cattle world wideH. rufipes – attacks cattle and hoses in AfricaH. maculala – attacks cattle and horse in tropics and subtropics

o adults are 10 cm in length and pale reddish brown in coloro with yellow spots or bands wings extend beyond the margin of the abdomen proboscis are retracted when not feeding

Life cycle:Female lays 1 larva at a time (max. Of 5-6) in dry soil or humus→ pupates almost immediately and change its

color from yellow to black → pupal period may be a month or longer

Habits:1. adult flies are more frequent in warm weather2. preferably bites on the hind legs and pubis but may bite another body parts3. they are strong fliers but could not travel long distances4. remains on the host for long periods and are not easily disturbed; when disturbed, they move sideways like a crab

Pathogenic effects:1. annoyance to animals which are not accustomed to attack2. transmits Trypanosoma theilieri of cattle/carabaos and Haemoproteus of anatids and birds3. mechanical transmitter of B. anthracis

Control:1. topical application of insecticides with repellant and residual effects (pyrethrin)

Pseudolynchia maura/cauariensis “pigeon lousefly or pigeon fly”o attacks pigeons and wild birds in the tropicso resembles sheep ked but have wings; dark brown in coloro well-developed wings which extent beyond the tip of abdomeno wing venation reduced and concentrated anteriorlyo female produces 4-5 young during life

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Life cycle:Larvae are laid in dark crevices of pigeon houses, in dry dust or nests (a female produces 4-5 larvae in an lifetime

of around 43 days → pupates in a few hours after deposition which lasts for 23-30 days in warm weather→ adult (copulation takes place on the host)

Habits:1. moves rapidly through feathers2. fast fliers; not easily caught and handled

Pathogenic Effects: 1. serve as i.h of haemoproteus columbae “pigeon malaria”2. suck blood and cause painful wounds in 2-3 weeks squabs3. cause anemia in young pigeons

Control:1. dust birds with 5% pyrethrum powder, 5% rotenone powder2. regular or thorough cleaning of pigeon loft

Lepopthena cervi “deer ked”o both sexes are winged but when the female found a host, the wings breaks off and resemble

Melophagus ovinus

Melophagus ovinus “sheep ked”o wingless with strong legs and stout clawso with brown hairy bodyo more common in temperate countrieso longetivity of males – 90 days; females - 120 days

Life Cycle:Female attaches its single immobile larva (max. of 10-20 larvae) to the wool by means of a sticky

substance→pupates within 12 hrs into a chestnut brown pupa (pupal period is 20-45 days) → adult → copulation begins after 3-4 days (gestation period is 10-12 days)

Habits:1. permanent ectoparasite2. enorged female may live up to 8days off the host3. pupae removed from the sheep could still “hatch” if the temperature is favorable but will die soon if they could not

find a sheep to feed on

Pathogenic significance:1. anemia2. wool damage – severe irritation will cause the animal to bite, rub, or scratch itself; ked’s feces stain the wool

which don’t wash out readily3. transmits Trypanosoma melophagium which is actually non-pathogenic4. heavy infestation causes emaciation, unthriftiness, loss of condition, and anemia5. predisposes the sheep to “blowfly strike”

Control:1. shearing to remove pupa and adults2. dipping, spraying or dusting with dieldrin, aldrin, coumaphos, chlordane etc.

ORDER HEMIPTERA (Bugs)

General characteristics:1. body flattened dorsoventrally2. jointed proboscis and flexed under the head when not in use3. blood suckers4. wing may or may not be present

CIMICIDAE (BEDBUG OR SUROT)24

Cimex lectularius “common bedbug” – attacks mammals and poultryC. hemiptereus “oriental bedbug” – attacks mammals and birdsHaematosiphon inordorus – attacks poultry in US and Mexico

o vestigial wingso body covered with thick bristles and hairso adult has a pair of ventral thoracic stink glands while the nymph has dorsal abdominal stink gland

responsible for the characteristic bedbug odor

Life Cycle:Direct development (egg → nymph → adult)Female lays 150-200 eggs in batches of 10-3- in the cracks and crevices in floor, bed, and other objects →egg

hatches in 3-14 days→ nymph resembles adult except in size→ molts 5 times in 6-8 months→ adults develops after 4-6 weeksAdults lives for a year or more

Habits:1. nymphs and adults are blood suckers2. survives long period of starvation (adults – at least 1 year; nymph – 70 days)3. nocturnal feeders but may bite even during day time

Pathogenic effects:1. severe irritation and anemia in poultry2. in man, causes allergy, asthma, insomnia and nervousness3. may produce influenza-like symptoms4. transmits Pasteurella spp (plague), leprosy virus, Leishmania donovani (kala-azar), Trypanosoma cruzi (Chagas

dss), Rickettsia sp (relapsing fever), and Leptospirosis

Control:1. eliminate hiding places2. fumigation of hiding places with methyl bromide3. spray bedframes and mattresss with 1% chlordane

REDUVIIDAE (Kissing Bugs)Triatoma rubrofaciata, T. sanguisuga, T. protractaPanstrongylus spRhodnius sp.Reduvius sp.

Life Cylcle:Females lays egg singly (about 100-3 eggs) in dusty corners or on ground cracks and crevices→ hatch into

nymph in 1-4 weeks → nymph molts 5x over several weeks→ adultsEntire lfe cycle takes 1-2 years

Habits:1. parasitic on man and animals2. nocturnal feeders3. defecate on skin of host during feeding

Pathogenic effects:1. cause painful bites2. serve as i.h and transmitter of Trypanosoma cruzi “chagas disease” in man

Control1. screen houses or use mosquito net2. eliminate hiding places3. spray with insecticides

ORDER ORTHOPTERA (COCKROACHES)

General Characteristics

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1. possess 2 pairs of wings, the anterior mesothoracic pair which is thickened and the posterior or metathoracic pair which is membranous

2. antenna is long, filamentouos and many jointed3. mouthparts and adapted for chewing4. dorsoventrally flattened with size ranging from 1 cm to several cm long5. moves rapidly since their legs are fit for running

Blatella germanica “german roach or croton bug” – small, light brown in color with 2 longhitudinal black stripes prothorax and wings

Blatta orientalis “oriental cockroach” – large, dark brown; wings vestigial in female and not reaching tip of abdomen in male

Periplaneta americana “American roach” – 1.5 inched, chestnut brown; pronotal markings less defined and the last segment of cercus twice as long as it is wide

Periplaneta fuliginose – smokey brown in color; pronotum solid dark brown to blackPeriplaneta australasiae “Australian roach” – resembles P. Americana but pronotum has yellow borders Supella superlectilium – tropical cockroach with 2 brown cross band on tegmina

Life Cycle:Eggs are laid in egg cases (ootheca) and deposited in crevices (no. of eggs/ootheca - 16-24)→ egg capsule may

be carried in the ovipositor for several days or weeks but in most cases are deposited in 1-2 days in crevices→ after 30-80 days eggs hatch into nymph (white in color, wingless)→ molts 5-6x to become adult in 10-12 monthsLife span of adult – 1-2 years average

Habits:1. nocturnal – active at night and hide in dark, humid places during the day2. scavengers – feed on excrement, sputum, decaying organic matter, human and animal food3. omnivorous – nymph and adults prefers starchy and sugary foods but will eat anything from dead insects to dried

or fresh blood, vegetable, cheese, grains etc4. gluttonous – even when a stomach is full, when they find a better food, they disgorge the stomach contents and

eat again; defacates anywhere5. can survive without food for five months6. prefers warm places

Pathogenic effects1. not parasitic, it is a household pest2. omnivorous habits cause damage to materials3. leaves a “roachy odor” from gland secretions that spoils food with which it comes in contact with4. it is a potential mechanical transmitter of the ff:

a. bacteria around 40 enterobacteria anthrax tetanus pneumonia TB Diphtheria Brucellosis

b. Fungal Infection Aspergillosis

c. Protozoa Entamoeba Giardia sp Balantidiam Coli Trichomonas sp

5. it serves as i.h or cyclic transmitter of the followinga. Oxyspirurs mansoni – eyeworm of chickenb. Tetrameres Americana – proventricular worm of chickenc. Physaloptera praepatialis – stomach worm of dog and catd. Gongylonema neoplasticum – produce malignant tumors in rats

Control

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1. cleanliness2. 2. application of insecticides in hiding places

a. 2.5% chlordaneb. 1.5% malathionc. baygon, raid, shelltoxd. Molasses bait trape. Birth control spray – sterilize the roaches and stops breeding

ORDER COLEOPTERA (BEETLES)

General Characteristics1. comprises the largest order (40%) of the class insecta2. leathery integument3. with 2 pairs of wings; anterior pair is horny (elytra)4. with mandibulate mouthparts5. complete metamorphosis6. produce a vesicating substance called cantharidin which is found in the whole body primarily in the elytra

Important families:1. Staphilinidae “rove beetles” – larvae and adult feeds on dung, decaying animal matter etc2. Silphidae – “burying beetles”; feeds on dead animals and decomposing flesh3. Dermestidae – “hide beetles”; feeds on dead animals, cured meat, cheese, cereals, dried flesh, blood etc

(Dermestes ater; Attagenus megatona)4. Tenebrionidae – Tribolium castaneum; T confusum “grain beetles” – common feeds5. Cucijidae – Cryptolestes Ferrogineus6. Cusculionidae – Setophilus oryzae (rice weevil); S. zeamais (corn weevil)7. Meloidae – Blister beetles

Pathogenic Effects:1. potential transmitter of B. anthracis and other pathogens2. cyclic transmitter of the following

a. Ascarops strongylina – stomach worm of pigb. Physocephalus sexaiatus – stomach worm of pigc. Gongylonema pulchrum – esophagus of pig and rumen of ruminantsd. Macranthorhynchus hirudinaceus – thorny headed worm of pige. Spirocerca lupi – nodules in the aorta, esophagus, and stomach of dogsf. Physaloptera preputialis – stomach worm of dog and catg. Moniliformis moniliformis – small intestine of rodentsh. Hymenolepis nana – tapeworm in the SI of ratsi. Raillietina cesticillus – tapeworm in the SI of chickensj. Hymenolepis carioca - tapeworm in the SI of chickensk. Choanotaenia infundibulum – tape worm of chicken

3. some beetles are poisonous to chickes, duckling and turkeys; letal in 24 hours e.g. Macrodactylus subspinosus4. some beetles cause blister formation. E.g. Lytta vesicatoria “Spanish fly beetle”5. other spp of blister beetles: Sessinia collaris “skin blister/ coconut beetles; Sessinia decolor “skin blister beetle”;

Oxicopis vittala; Epicauta pestifera; Zonabris nubica

Control1. cleanliness2. spray insecticides

ORDER SIPHONAPTERA (FLEAS OR PULGAS)

General Characteristics:1. wingless with laterally compressed bodies2. chitinous glossy covering is thick and dark brown3. compound eyes are absent but some have simple eyes4. abdomen has 10 segments, the 9th bears a dorsal plate called sensilium or pygidium which is covered by sensory

setae

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5. the tergum of the 9th abdominal segment is modified to form the claspers6. the penis (aedeagus) is chitinous and coiled7. the 3rd leg pair are much longer than the rest which are adapted for leaping8. the head may bear dark spines called “combs” or “ctenidia”9. the antennae are 3-segmented, club-shaped located in a groove behind the simple eye10. mandibles are cutting structures11. not markedly host specific

Important species:1. Echidnophaga gallinacea “stick tight flea”- affects chickens in southeastern US; head is angular; no ctenidia; may

attack other animals like horse, cattle, dogs, rats, etc.2. Tunga penetrans “sand flea or jigger”- affects man primarily but may also attack pigs, rats, skunks, etc; thorax

reduced; frons sharply angled or angular3. Pulex irritans “human fleas”- affects man and other mammals; genal and pronotal ctenidia absent; mesopleural

rod absent; smoothly rounded frons4. Xenopsylla cheopis “oriental rat flea”- occurs in brown rats but readily bites man; common in brown and black

rats; frons smoothly rounded; mesopleural rod present; genal and pronotal ctenidia absent5. Ctenocephalis felis et felis “cat flea” – oral and pronotal ctenidia present; frons pointed; 1st oral/genal ctenidia

about as long as the 2nd; head is elongated; most common species in dogs and cats6. Ctenocephalides canis “dog flea”- less common than Ct. felis; occurs in both dogs and cats; 1st spine about half

as long as the 2nd; head is rounded7. Ceratophyllus fasciatus “northern rat flea” – present in the Philippines; occurs in rodents; oral ctenidia present;

pronotal ctenidia present8. Ceratophyllus gallinae- chickens9. Ceratophyllus niger- chicken10. Leptopsylla cuniculli- rabbit flea11. Leptopsylla segins “mouse flea”- presence of vertical genal ctenidia

Life cycle:

Female flea lays up to 20 eggs at a time and some 400 to 500 during her lifetime Eggs are deposited in dust or➭ dirt[dried fecal matter] eggs hatch in 2-16 days [average of 7-9 days], larvae are slender, 13 segmented, yellowish➭ white in color, with long bristles; it has chewing mouthparts and subsist on dried blood, feces and organic matter; the last abdominal segments bears two hooked processes called “anal struts” which are used for locomotion and for holding on to strata after 7-10 days, it becomes a pupa adult➭ ➭

The life cycle ranges from 3 to 6 weeksLife span without food: 1-4 months; with food: 3-34 months

Pathogenic effects:

1. Directa. allergic flea bite dermatitis or chronic non-specific dermatitisb. irritation and wounds from scratching to relieve itchinessc. cause ulceration and subsequent bacterial infection in the feet (Tunga penetrans)d. may cause module formation and ulcers in the comb and wattles and around the eyes of chickens as

Echidnophaga gallinacea burrows deep into the skin2. Indirect

a. mechanical transmitter of the ff: Xenopsylla cheopis- Bubonic plague (P. pestis) and Typhus (R. typhi) Leptopsylla cuniculi- transmits myxomatosis of rabbits

b. serve as intermediate host of the ff: Ctenocephalides felis, C. canis, P. irritans- Dipylidium caninum of dog, cat and man C. canis and C. felis- Dipetalonema reconditum C. fasciatus and X. cheopis- Hymenolepsis diminuta C. canis, P. irritans, X. cheopis- Hymenolepis nana C. fasciatus- Trypanosoma lewisi

Treatment and control:1. give corticosteroids as palliative treatment if there is much distress in flea-bite allergy

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2. application of insecticides on hosts and surroundings3. burning of litter and debris; maintain cleanliness

ORDER PHTHIRAPTERA

General Characteristics:1. dorsoventrally flattened2. wingless3. most are blind but a few have primitive eyes which are merely photosensitive spots4. legs terminate in claws (mammals- 1 claw; birds- 2 claws)5. permanent ectoparasites; most being unable top survive away from the host for more than a day or two6. head, thorax and abdomen distinct7. incomplete metamorphosis8. entire life cycle is spent on the host

Two Suborders:1. Anoplura “sucking lice”2. Mallophaga “biting lice”

SUBORDER: ANOPLURA

Character differences between suborders Anoplura and MallophagaAnoplura Mallophaga

Head Usually pointed anteriorly Broader than the thorax

Mouthparts adaptationSucking (blood is contained in the haustellum)

Biting or chewing

Source of food Blood and tissue fluidsEpithelial debris, dried blood and serum

Eyes Present in pediculidae Vestigial

Number of claws1 (aided by a tibial spur or tibial pad)

1 or 2

Hosts Mammals only Mammals and birds

Thorax Small; all segments are fusedIndistinctly segmented (meso and metathorax are fused)

Paratergal plate Present Absent

AntennaReadily visible at the sides of the head

May or may not be visible at the head sides

Host and site specificity Not highly site specific Highly site specific

Habits of Anoplura:1. slow-moving but have a powerful leg2. attach their eggs individually to hairs of host or in the case of human body louse, to the fibers of the host’s clothing3. with 3 nymphal stages living and feeding in the same way as the adult; all stages feed on the host’s blood and

maintain contact with their host by a number of relatively simple responses4. Pediculus and Hematopinus sp. respond to warmth and smell5. they are thigmotactic- move less in rough surfaces6. Negatively phototactic- move toward dark objects7. Live at relatively high temperature but leaves the host at too high temperature as in fever and transfer to another

host

Important families:HematopinidaeLinognathidaePediculiidae

Character Differences among the families of Anoplura

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Hematophinidae Linognathidae Pediculidae

Paratergal plates Marked AbsentPresent

Leg pairs Similar sizes 1st pair is smallest Similar sizesTemporal angles Present Absent AbsentEyes Absent Absent PresentRow of hairs on abdominal segment

1 Many

Size Large Small Medium

HEMATOPINIDAE (SHORT-NOSED LOUSE)

Hematopinus tuberculatus- carabao and buffaloes in Asia and PacificH. quadripertusus- cattle and buffalo in temperate and trophic regionsH. eurysternus- cattle (absent in the Philippines)H. buffalo- buffaloes in South AfricaH. suis- swine; largest anopluran found in domestic animalsH. asini- horses

Life cycle:

Eggs or “nits” attached to hair close to the skin at the region of the neck, shoulder, flank and lower abdomen after a blood meal eggs hatch into 1➭ st nymphal stage after 2-3 weeks nymphs molts 3x within 15 days (5 days/molt) ➭ ➭ adult sexually mature after 3 days ➭

Entire life cycle: 23-32 days

LINOGNATHIDAE (LONG-NOSED LOUSE)

Linognathus vituli- cattle; present in the Philippines; “long-nosed cattle louse”L. africanus- goats and sheep “sucking louse of sheep and goats”L. stenopsis- goatsL. pedalis- sheep “foot louse of sheep”L. ovillus- sheep “body/blue/face louse of sheep”L. setosus- dogs “canine sucking louse”Solenopotes capillatus- cattle, “tubercled lice”; reported from imported cattle

Life cycle:Eggs (dark blue in color) attached to the hairs of the dewlap, sides of the neck and face or anywhere in heavy infestation eggs hatch into nymph after 10-13 days nymph molts 3x within 15 days➭ ➭Entire life cycle: 23-27 days

PEDICULIIDAE

Pediculus humanus capitis “human head louse”P.h. corporis “human body louse”Pediculus eurygaster- macaqueP. obtusus- monkeys, baboonsPhthirus pubis- crab louse or pubic louse; occurs in the pubic region; may also occur in the armpit, eyelashes, eye brows, beard, mustache

Life cycle:Eggs are attached to the hairs eggs hatch into nymph after 5-10 days nymph molts 3x within 21 days adult➭ ➭ ➭

Entire life cycle: 3-4 weeks

Other important families:Hoplopleuridae

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Echinophthiridae

HOPLOPLEURIDAE

Polyplax serrata- mousePolyplax spinulosa- mouse ratHoplopleura acanthopus- miceH. captiosa- mouseH. pacifica- ratsHaemodipsus ventricosus- rabbit

Paratergal plates project apically from the body Tergal and sternal plates usually distinct

ECHINOPHTHIRIDAE

Antarctophthirus microchir- host are sea lions Body densely clothed with thick setae sometimes modified into scales

Effects of sucking lice on the host:1. cause irritation, pruritus and subsequent biting and scratching resulting to thickened, pigmented and darkened

skin (Vagabond’s disease), shaggy, rough, matted hair coat and hair ball in the stomach2. restlessness and interrupted feeding results to loss of weight and reduced milk/meat yield3. considerable anemia4. lameness (foot louse)5. reduce body resistance to viral and bacterial diseases6. Hematopinus suis may transmit African swine fever virus and swine pox virus7. The body louse is a vector of:

a. Rickettsia prowazeki (Epidemic typhus)b. Rickettsia Quintana (Trench fever)c. Borrelia recurrentis (Relapsing fever)d. Yersinia/Pasteurella pestis (Plague)e. Pasteurella tularensis (Tularemia)f. Poliomyelitis virus

8. attracts myiasis flies

SUBORDER: MALLOPHAGA

BITING LICE OF MAMMALS:Damalinia bovis/Trichodectes scalaris- cattle; absent in the Phils; present in the USD. equi- horsesD. ovis- sheepD. limbata- goatsTrichodectes canis- reported in the Philippines but not commonHeterodoxus spiniger- dogs; most common biting louse of dogs in the PhilippinesHeterodoxus longitarsus- kangaroos, wallabiesFelicola subrostratus- cats; common in the Philippines especially stray catsGyropus ovalis- guinea pig and other rodents; present in the PhilippinesGliricola porceli- guinea pig and other rodentsTrimenopon hispidum- guinea pig

Life cycle:

Eggs are attached to the hairs close to the skin of the host eggs hatch into nymph in 5-8 days molts 3x within ➭ ➭3-4 weeks adult➭

Entire life cycle: 26-30 days

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Effects on the host:1. severe irritation and restlessness2. Trichodectes canis and Heterodoxus spiniger serve as intermediate host of Dipylidium caninum3. Pruritus and consequent skin lesions due to scratching4. reduced production due to interrupted feeding

Control:1. spray/ dip livestock with insecticides (0.06% coumaphos; 0.5% malathion; 0.5% chlordane; 0.15% neguvon; 0.5%

sevin; 0.5% coumaphos)2. dusting with 5% malathion dust or 5% sevin powder3. apply ointment (5% rotenone in 10 parts petrolatum)4. ivermectin5. shave carabaos and buffaloes during summer

BITING LICE OF POULTRY

Chicken: Menopon gallinae- shaft louse Menacanthus stramineus- body louse M. pallidulus- small body louse M. cornutus- body louse Lipeurus caponis- slender wing louse Oxylipeurus dentalus- neck louse Goniodes dissimilis- brown louse Goniodes gigas- large body louse Goniocotes gallinae- fluff louse Cuclotogaster heterographus- head louse; absent in the Philippines

Turkey: Menacanthus stramineus Menopon gallinae Chelopistes/ Goniodes meleagridis Oxylipeurus polytrapezius

Pigeon: Menopon giganteum Columbicola columbae- most common Campanulotes bidentalus Colphocephalum turbinatum

Duck and geese: Trinoton anseris Menopon gallinae Anaticola crassicornis Anaticola anseris Holomenopon leucoxanthum- causes “wet feather” in ducks

Quail: Menopon gallinae Goniocotes spp.

Life cycle:Eggs are attached to the base of the feather, singly or in cluster (pair of lice may produce 120,000 adults in a few

months)Entire life cycle: 2-3 weeksLife span: several months on the host; 5-6 days off the host

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Effects on the host:1. unthriftiness and loss of weight2. anemia3. lowered production4. Menacanthus stramineus is the injurious of the poultry lice5. M. stramineus may carry equine encephalitis virus6. M. gallinae transmits ornithosis

Control:1. spray/ dust insecticides on large flocks (Malathion, Sevin, Neguvon, Coumaphos)2. dip birds on insecticides (small number of birds)3. repeat application after 2 weeks to prevent nymphs from reaching maturity then 2x a year

CLASS ARACHNIDA

General Characteristics:

1. body is not divided into head, thorax, and abdomen; it is subdivided into:a. gnathosoma - mouthparts and the plate that bears it, the capitulum or gnathobase in spiders and

scorpions which bears teeth that helps in chewing the preyb. podosoma - bears the legs (maybe further subdivided into propodosoma and metapodosoma)c. Opisthosoma - posterior part behind the 4th pair of legd. Idiosoma - consists of podosoma and opisthosoma

2. wingless3. antennae, compound eyes and mandibles are absent4. possess toxic glands and claws (spiders and scorpions) which they use to paralyze their host and prey on them5. breathe through lung books and trachea6. larval stages have 3 leg pairs, nymphs and adults have 4 pairs

Components of the mouthparts of arachnids:

1. chelicerae - first appendage; consists of a pair of cutting structures for food processing2. pedipalps - second appendage; segmented structure lateral to the chelicerae for grasping, locomotion and

reaction to stimuli3. hypostome - median structure with recurved teeth for anchorage

General stages of development:

1. egg- oval or spherical2. larva- with 3 leg pairs3. nymph- with 4 leg pairs without sexual organs

a. protonymph- 1st instarb. deutonymph- 2nd instarc. tritonymph- 3rd instar

4. adult- with 4 leg pairs and well-developed sexual organs

Class Arachnida

Order Acarina (ticks and Mites)Suborder Ixodoidea (Ticks)

Family Argasidae (Soft ticks) Argas Otobius Ornithodorus

Family Ixodidae (Hard ticks)BoophilusRhipicephalusAmblyommaIxodes

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DermacentorHyalomma Amblyomma HaemaphysalisAponomaRhipicentorMargaropus

Suborder Mesostigmata (Mites)Suborder Thrombidiformes (Mites)Suborder Sarcoptiformes (Mites)

Order Araneidea (Spiders)Order Scorpioneidea (Scorpions)

Some important differences between Argasidae and IxodidaeArgasidae Ixodidae

ScutumAbsent

Present- covers small portion of dorsal surface in female and the entire dorsal portion in males

Sexual dimorphism Not marked Distinct Mouthparts and capitulum Ventral; subterminal Anterior Palpi Leg-like (flexible) Rigid Festoons Absent Generally presentCoxa Unarmed Generally armedFeeding habit Moderate but frequent One large mealEgg laying habit Small batches One large batch

Life spanSeveral years (5 years or more)

<1 year; rarely 2 years

Nymphal stage Usually 2 or more Usually single

Feeding habitContinues to lacerate the capillaries by the chelicirae

Secretes a cement that binds the mouthparts firmly to the skin to prevent the blood from leakage

Adaptation to environment Drought resistantCannot withstand dry conditions

ARGASIDAE (SOFT TICKS)

Characteristics:1. eyes are absent or there may be 2 pairs situated laterally on the supracoxal folds2. the margin of the body is distinctly flattened forming a lateral sutural line3. the dorsal surface often bears small, rounded “buttons” with a pit in the middle which often bears a hair

Argas persicus- fowl tick; found in domestic poultry in the tropics but not in the PhilippinesA. reflexus- found in pigeons

distinctly flattened body leathery integument bears “buttons” and “plates” larvae can live for 3 months without food nymphs and adults survive starving for about 5 years nymph and adult spend most of their time hiding on cracks and crevices they are nocturnal feeders and remain on the host only for few minutes

Life cycle:Female lays eggs in batches of 20-100 eggs (total of about 700) in cracks and crevices of poultry houses after a

blood meal hatch into larvae in 2 weeks- 3 months larvae attach to the host and feed for 5-10 days drop and hide to➭ ➭ ➭ molt into protonymph after 7 days nymph reattaches to the host and becomes angorged becomes a deutonymph after➭ ➭ 2 weeks after another 2 weeks adult➭ ➭

Pathogenic effects:

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1. restlessness at night resulting to loss of productivity2. causes anemia in heavy infestation3. causes tick paralysis in ducks4. transmit the ff:

a. Borrelia anserine (fowl spirochetosis)b. Aegyptienella pullorum (Avian piroplasmosis/ Aegyptienellosis)

Control:

1. remove birds from houses and place in wooden crates, the larvae will then drop off within 10 days; spray the poultry houses before returning the birds

2. clean poultry houses and spray cracks and crevices with acaricides

Otobius megnini “spinose ear tick” larval and nymphal stages are ear parasites of dogs and other domestic animals including man absent in the Philippines integument bears spine-like processes adults are non-parasitic female may lay up to 600 eggs oviposition may last for 6 months, after which the female dies but the unmated female lives longer than a year the nymph may remain in the ear for as long as 4 months before it drops off to molt into adults unfed larvae can live for 19-63 days at room temperature

Pathogenic effects:

1. irritation and inflammation of the ear canal; secondary bacterial infection may extend inwards with serious results2. loss of condition3. animal exudes waxy or oily material from the ears that the animal tends to shake the head and scratch the ears

Treatment: Instill 1 part 40% chlordane emulsion and 15 parts pine oil or 1 part hexacholorcyclohexane 2 parts xylol and 17

parts pine oil

Ornithodorus moubata- attacks man, domestic and wild animals including birds in AfricaO. savignyi- affects domestic animals and man in Africa and IndiaO. turicata- affects domestic animals and man in US

Particularly are resistant to adverse conditions because of the crystalline cuticular wax coating over the body which is protected by a cement layer and prevents water loss through the cuticle

No feces are passed out through the anus, the coxal apparatus which opens just behind the coxae of the first leg pair, excretes the waste

Larvae do not hatch but remain quiescent until they molt into nymph in the egg; adult and nymph attack the animal

Pathogenic effects:1. nymph and adults cause irritation and blood lo0ss anemia resulting to lowered production2. O. moubata is a reservoir host for African Swine fever virus and African relapsing fever (Borrelia recurrentis)3. O. moubata is also a vector of Coxiella burnetti (O. fever), A. pullorum and B. anserine4. O. turicata transmits O. fever, Anaplasmosis, Theileriosis and cause tick paralysis in sheep

IXODIDAE (HARD TICKS)

Characteristics:1. some species may have a series of “marginal grooves” or a row of posterior notch called “festoons”2. genital opening is in the ventral midline; anus is posterior3. eyes, when present, consist of 1 pair situated on the lateral margin of the scutum4. male may have ventral plates5. some species may have colored, enamel-like areas on the body (ornate ticks), the inornate ticks have not6. unfed ticks live longer than the well-nourished ticks7. males remain much longer on the host than female (4 months or longer) and consequently accumulate on the

host; if no male is present on the host, the female may remain attached for much longer periods than under normal conditions

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Classification of ticks based on the number of hosts to which they attach during their parasitic life cycle:

1. One-host tick- the entire parasitic development takes place on one host (larvae attaches to a host, molt into nymph and finally to the adult stage on the same animal)e.g. Boophilus microplus, B. annulatus, B. decoloratus

2. Two-host tick- larvae and nymph occur on one host and the adult on another host (larva attaches to a host, molts into nymph then drops to the ground after engorgement, molts again on the ground to become an imago and seeks another hoste.g. Rhipicephalus bursa, R. evertsi

3. Three-host tick- each stage of development takes place on different or the same hosts (they drop to the ground every after engorgement and molt on the ground)e.g. Rhipicephalus appendiculatus, R. sanguineus, Ixodes ricinus

Life cycle:A batch of 2000-20,000 eggs are laid (after oviposition, the female dies; male dies after mating) after 3 weeks,➭

the newly hatched larvae (seed ticks) emerge which climb on grass blades and shrubs and wait until a suitable host passes after engorgement, the first and the only nymphal stage emerges either on the host or on the ground➭ ➭ development of the imago on the host or on the ground after the nymph has engorged once the integument hardens➭ (usually after copulation), the female drops off; the female seeks a sheltered spot to lay her eggs

IxodesIxodes ricinus “castor bean tick”

Affects wild and domestic animals in Europe and Australia Principal species associated with “tick paralysis” in cattle Three-host tick Transmits babesiosis cattle, anaplasmosis, louping ill, rickettsial tick borne fever of sheep and tick pyemia of

lambs caused by Staphylococcus aureusIxodes canisuga “British dog tick”Ixodes rubicundus “paralysis tick of Southern Africa”Ixodes holocyclus “paralysis tick of Australia”Ixodes scapularis “black-legged tick”- attacks livestock, dogs and cats

BoophilusBoophilus annulatus “North American cattle tick”, “Texas fever cattle tick”

One-host tick Transmits Babesia bigemina (Texas fever or bovine piroplasmosis)

Boophilus decoloratus “blue tick” One-host tick Affects cattle in Ethiopia Transmits Babesia bigemina, Anaplasma marginate and Borrelia theileri of ruminants

Boophilus microplus “tropical cattle tick” Most common cattle tick in the Philippines One-host tick Primarily affects cattle but can be found in carabaos, buffaloes, sheep, goats, horse and deer Transmits Babesia bigemina, B. bovis, Anaplasma marginale, Coxiella burnetti and Borrelia theileri

Life cycle:Female lays 2,000-4,400 eggs on the ground hatch into larvae within 3 weeks larva finds a host and feed on➭ ➭

blood for 4-5 days molts into nymph after 2 days on the host nymph feeds for 5-6 days molts to become an adult➭ ➭ ➭ ➭ copulation takes place on the host egg deposition lasts for about 2 weeks➭

Entire life cycle: 50 days; larvae may survive unfed for 90 days or longer

RhipicephalusRhipicephalus appendiculatus “brown ear tick”

Affects wild and domestic animals of Africa Three-host tick Transmits theileriosis (Theileria parva and T. mutans), Hepatozoon canis, Babesia bigemina and Rickettsia canori

(tick bite fever)R. evertsi “red-legged tick”

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Affects wild and domestic animals in Africa Two-host tick Transmits Theileria mutans and T. parva (Eastcoast fever), Babesia bigemina, Babesia equi, and Hepatozoon

canisR. bursa

Transmit Babesia ovis, B. equi, Theileria ovis, Anaplasma marginale, Coxiella burnettiR. sanguineus “brown dog tick” “kennel tick”

Common in the Philippines Primarily affects dogs but may occur in a wide variety of birds and mammals Three-host tick Transmits Babesia canis, B. equi, B. caballi, Ehrlichia canis, Hepatozoon canis, Rickettsia canis, Pasteurella

tularensis and Coxiella burnetti May cause tick paralysis

Life cycle:Female lays 2,000-4,000 eggs on the ground egg hatches into seed tick in about 3 weeks; larvae may be found➭

on walls, ceilings, floors, curtains, chairs, etc. they attach to the skin of the dog to feed after feeding for about a week,➭ ➭ larva drops to molt into nymph after 1-2 weeks, the second nymphal stage develops after the 1➭ st nymphal attaches to a host again after the nymph feeds for about 5 days then drops off and molt to adult in about 10-70 days adults attach to➭ ➭ the host again and become engorged in 1-3 weeks drops off to lay eggs➭

Unfed larvae survive for 8 months, nymph for 6 months, adults for 19 months

DermacentorDermacentor reticulatesD. variabilis “American dog tick”D. nitens “tropical horse tick”D. albipictus “winter tick”D. occidentalis “moose tick”D. andersoni/venustus “rocky mountain wood tick”

Three-host tick Ornate Causes tick paralysis Transmits Rickettsia rickettsii (D. andersoni is the primary vector), Anaplasma marginale, Babesia canis, Coxiella

burnetti, Leptospira Pomona

HaemaphysalisH. leachi leachi “yellow dog tick”

Found in domestic and wild carnivores in Africa and Australia Transmits Babesia canis, Rickettsia conori, and Coxiella burnetti

H. leporis-palustris Present in the US Transmit Q fever, tularemia and Rickettsia rickettsii

HyalommaH. truncatum

Causes “sweating sickness” in cattle

AmblyommaA. hebraeum “bont tick”A. variegatum “tropical bont tick”A. americanum “lone star tick”

Characterized by the presence of white spot on the scutum of female Three-host tick Transmits Rickettsia ruminantium (heartwater disease), Q fever. Tularemia and RMSF

Aponomma Occurs almost exclusively in reptiles (phytons, snakes, lizards, etc.)

RhipicentorR. bicorinis

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R. nuttali Present in large animals Disease relationships are unknown

MargaropusM. winthemi “argentine tick”

Attacks horses and cattle One-host tick

M. reidi Affects giraffe in Sudan With beady-legged tick

General pathogenic effects of ticks on their hosts:1. bite injuries2. hosts are predisposed to myiasis and pyemia3. “tick worry” results to losses in production4. anemia (single adult female could suck 0.5-3.0 ml of blood)5. transmits viruses, bacteria, rickettsia and protozoa6. secretes toxins that cause “tick paralysis”-ascending type which terminates in death due to respiratory failure7. cause “sweating sickness” due to toxins secreted by Hyalomma truncatum

Control:1. application of acaricides (CHC, organophosphates, carbamates, arsenic) by spray, dust, bath/dip which must be

repeated after 12 days then every 21 days thereafter; dipping/spraying at 12 days interval give excellent results2. hand picking3. burning of pastures, land cultivation, pasture rotation and “pasture spelling”4. biological control

guinea fowl feeds on R. sanguineus Hymenopteran parasites of ticks- Ixodiphagus sp. and Hunterellus sp. Bubulcus ibis (egret or tagak) and martines feed on ticks Crosses of B. microplus and B. annulatus produce sterile offspring

Prevention of ticks:1. burning pasture to destroy eggs and larvae2. cultivation of land to bury eggs and larvae3. pasture rotation every 90 days4. spraying/dipping regularly at least 12 days interval

Control of dog ticks:1. hand picking2. spray acaricides3. dubbing – animal’s body, paws, ears4. dusting – sevin powder, asuntol(do not give to puppies), malathion – 0.5%, supona, barricade, PFI spray

etc.

dog house and kennels should be sprayed with acarides for young dogs care must be observe in selecting acarides to avoid poisoning

SUBORDER: MESOSTIGMATA

General Characteristics:1. possess a single pair of stigmata which are lateral and outside the third pair of coxae2. small, most not being less than 0.3 mm but may reach 1.0 cm when fully engorged3. body may be spiny or hairy4. mouthparts are long, slender and needle-like5. legs are long; extends beyond the body margins6. entire life cycle is spent on the host so that transmission is by direct contact7. there may be 2 or 3 nymphal stages prior to the adult stage8. most are obligate parasites

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DERMANYSSIDAE

DermanyssusD. gallinae “red mite of poultry”

affects the domestic and wild birds; also affects man in the temperate zone larvae do not feed red in color when newly engorged with blood nymphs and adults periodically visits the host (at night) only to suck; in between meals, they are found in cracks

and crevices cause irritation from bites and listlessness which results to drop in production transmits Borrelia anserine (spirochetosis), St. Louis encephalitis and eastern and western encephalitis

OrnithonyssusO. sylviarum “northern fowl mite”

affects the fowl and other birds in temperate countries cause pruritus, anemia, loss of weight transmits fowl pox, St. Louis encephalitis, and eastern and western encephalomyelitis

O. bursa “tropical fowl mite” attacks chicken and other birds common in the Philippines; known as “hanip” its color is red when newly engorged could not survive off the host for more than 10 days its pathogenic effects are similar with that of O. sylviarum larvae do not feed

Life cycle:Eggs (1-5) are laid in the nest or fluff of feathers especially around the vent eggs hatch into larvae in 3 days➭ ➭

molts into protonymph after 24 hours feed on the host and molt into deutonymph after 1-2 days, feeds on the host➭ ➭ again adult in 1-2 days➭

Entire life cycle: 6-8 months

O. bacoti “tropical rat mite” affects rats and man; common in the Philippines transmits Yersinia pestis (Bubonic plague), Rickettsia typhi (murine typhus) and Coxiella burnetii (Q fever) acts as intermediate host of Litomosoides carinii, a filarial nematode of rats

AllodermanyssusA. sanguineus “house mouse mite”

vector of rickettsial pox in man caused by Rickettsia acari

EchinolaelapsE. echidninius “spiny rat mite”

definitive host of Hepatozoon muris in rats

RailletiaR. auris

found in the external ear canal of cattle in America and EuropeR. Rhopkinski

found in the ears of antelopes

PneumonyssusP. caninum

found in the nasal passages and nasal sinuses of dogs in US, Hawaii and Australia causes reddining of the nasal mucosa, sneezing, head-shaking and rubbing of the nose

P. simicola found in the bronchi of rhesus monkey

SUBORDER THROMBIDIFORMES

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THROMBICULIIDAE (CHIGGER MITES OR HARVEST MITES)

General Characteristics:1. may or may not have a pair of stigmata on or near the gnathosoma2. highly developed palpi3. body is covered with dense hairs (feathered) giving them a velvety appearance4. adults have a deep furrow between propodosoma and metapodosoma making the body appear to have 2 parts5. nymph and adults are free living6. adult chiggers do not copulate7. larvae attaches itself to the host and hydrolyzes the cuticle by means of a salivary secretion, forming a tube called

stylostome through which the larva sucks up on the host’s tissue fluid

Thrombicula autumnalis larvae attack domestic animals, birds and man cause irritation, inflammation and pruritus; dermatitis results from secondary bacterial infection due to scratching adults live in the soil

Thrombicula akamushi adults live in the soil vector of Rickettsia tsutsugamushi which causes Mite or Scrub typhus or River Valley fever of man in Japan and

New Delhi (“akamushi” means larval mite in Japan and “tsutsugamushi” means river valley)

T. sarcina “leg itch” occurs in sheep in Queensland attaches on skin of pastern, coronet and heel of sheep

T. alfreddugesi affects mammals birds and reptiles, and man in the US

Neochongastia philippinensisN. americana

affects mammals, turkeys and quails produce skin lesions which reduce the value of dressed fowl

Life cycle:Eggs are laid on the surface of moist larva larva “tungao”hatches from the eggs in 10-12 days attaches to the➭ ➭

host and feed on tissue fluids for 2-10 days larva drops to the ground to become a nymph (non-parasitic) after a week➭ ➭ adult

Control:5. spray range with 1% malathion, chlordane or toxaphene to control nymphs or adults6. apply sulfur in petrolatum to the skin lesion

DEMODICIDAE

General Characteristics:1. worm-like, cigar-shaped, elongate with stumpy legs2. live in the hair follicles and sebaceous glands of various mammals3. a skin commensal4. host-specific5. with unusual life cycle because it has a 2nd larval form (protonymph) which is a hexapod6. in older animals, Demodex spp. may move deeper making it less accessible to surface acting acaricides7. has been found in the blood, spleen and lymph nodes

Demodex canis- dogD. ovis- sheepD. caprae- goat

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D. equi- horseD. bovis- cattleD. phylloides- pigD. folliculorum- manD. bubalis- carabaoD. cunuculi- rabbitsD. musculi- ratsD. gambiae- guinea pig

Life cycle: little understood but entire life cycle is spent on their hair follicle and sebaceous glands of the host’s skin male occurs at or near the skin surface the female oviposits 2-24 eggs in the hair follicleMorulate eggs are laid on the skin protonymph (2nd larval stage with 3 leg pairs) deutonymph (octapod) adult Entire life cycle: 20-35 days

Pathogenesis:Predisposing Factors:

5. age6. short hairs7. animal condition/nutrition8. intercurrent infection9. frequent bathing10. undue use of alkaline soap

Transmission is by direct contact. The pathogenesis is more complex than any other mange mites because immune factors play a large part in the occurrence and severity. The dam may carry genetically-transmitted factor resulting to immuno-deficiency to Demodex attack Demodex itself causes blocking of the cell-mediated immunity thus suppressing normal T-lymphocyte response

Forms of demodectic mange:1. squamous or localized

characterized by loss of hair, thickening and wrinkling of the skin which becomes scaly, “reddened” or “coppery red” in color

usually begins at the face region self-limiting; usually cures itself without treatment and recurrence is rare

2. pustular or follicular characterized by formation of “pustules” and necrotic foci” due to bacterial invasion the skin is highly reddened with blood and serum oozing from affected area “red mange” usually appear in the face, around the eyes, muzzle and forepaws but may cover entire body in

generalized cases animal is rendered disfigured after treatment

Diagnosis:1. deep skin scraping, deep enough to draw blood then examine in mineral oil or in 10% potassium hydroxide

Treatment:Treatment is difficult because of its immunologic origin, therefore should be done on the advanced stage of the

disease. It takes 1-2 months of treatment for the squamous type and up to 3 months for the pustular type1. give acaricide

mitaban (amitraz) 3-4 applications at weekly interval neguvon solution trichlorfon ivermectin

2. supportive treatment- antibiotics (especially if secondary bacterial infection complicates the condition), vitamins, mineral supplements

CHEYLETIDAE

Psorergates “Australian itch”P. ovis- sheep

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P. bos- cattle moves about rapidly that is why they are called “walking dandruff” cause non-suppurative lesions due to biting and scratching

Syringophilus S. bipectinatus- quills of fowl featherS. columbae- quills of pigeon featherS. uncinata- quills of pheasant and peacock feather

CheyletiellaC. parasitivorax “rabbit fur mite”C. yasguri- dogC. blakei- cat

causes mild dermatitis

PEDICULOIDIDAE

PediculoidesP. ventricosus “grain itch mite”

causes intense pruritus in man and domestic animals who acquire the infestation by access to infected grains and straw

MYOBIIDAE

MyobiaM. musculi

causes loss of hair and dermatitis in laboratory animals

SUBORDER SARCOPTIFORMES

General Characteristics:1. legs ends in suckers, claws or hairs2. some species produce nymphs that are adapted to resist adverse conditions called hypopial nymph or hypopi;

they are provided with hooks and suckers on legs3. males often have copulatory suckers on the tarsi or anal region4. they burrow deep into the skin forming tunnels which cause thickening of the skin rather than scab formation

SARCOPTIDAESarcoptesNotoedresCnemidocoptes

PSOROPTIDAEPsoroptesChorioptesOtodectes

ANALGESIDAE (FEATHER MITES)Megninia

DERMOGLYPHIDAEPterolichus

SARCOPTIDAE

General Characteristics:1. globose or round body and striae of skin are interrupted by scales and spinose areas2. with long legs; the 3rd and 4th pair do not propel from the margin of the body3. anus is terminal which is ventral or dorsal in position4. permanent parasites of the skin, feathers and hairs of the host

SarcoptesSarcoptes scabiei variabilis canis- dogS.s. var. felis- cat

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S.s. var. suis- pigS.s. var. equi- horseS.s. var. ovis- sheepS.s. var. bovis- cattleS.s. var. cuniculi- rabbitS.s. var. caprae- goatS.s. var. bubalis- buffalo

tarsi of the 1st, 2nd, and 4th pair of legs end in bell-shaped suckers in male while the 3rd leg pair end in bristles; in female, the 1st and 2nd leg pair terminate in bell-shaped suckers while the 3rd and 4th end in bristles

legs with long, unjointed pedicel

Life cycle:

Female lays a total of 40-50 eggs in the skin (tunnels) one at a time at a rate of 3-5 eggs daily six-legged larvae emerges after 3-5 days (some emerge from the breeding tunnels and wander on the skin, but some remain in the parent tunnel or side pockets of it and continue their development there as far as the nymphal stages) larva molts into protonymph after 4-6 days deutonymph after 2 days (nymphal stages may stay in the larval pocket or wander and make new pockets) adult after 2-4 days (female remains in the moulting pocket until fertilized by a male; after mating, she extends the pocket into a tunnel or make a new one) after 4-5 days

Entire life cysle: 11-17 daysFemale life span is 3-4 weeks while the male dies after copulation

Pathogenesis:

Mite pierces the skin to suck lymph and feed on young epidermal cells marked irritation causes intense itching and scratching which aggravates the condition initial inflammatory response results to coagulative exudation forming a crust on the skin surface excessive keratinization and proliferation of connective tissue where the skin becomes much thickened and wrinkled

Clinical signs:1. In dogs

Loss of hairs Thickened, wrinkled skin covered with crusts Formation of papules with encrustation of lymph Rupture of papules with encrustation of lymph

2. In pigs Generalized focal erythema Pruritus and later encrustation on the ears and skin on the back region which may become very thick then

crack after leaving deep wounds which becomes invaded by secondary bacterial infection3. In horses

Papule formation and pruritus Formation of crusts and scabs which is associated with loss of hair Emanciation and cachexia

4. In cattle and carabao Rubbing against suitable objects Pruritus and bald patches on head and neck with marked thickening of the skin

Diagnosis:Demonstrate motes and eggs by skin scraping

Treatment:1. Dogs and cats

a. 12% sulfur in oilb. 1.5% sulfur-limec. 50% emulsion of benzyl benzoated. 0.5% chlordanee. 0.1% lindanef. amitraz

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2. cattle, goat, pig, horse (0.6% lime sulfur dip)a. 0.1% lindaneb. 0.25% malathionc. 0.25% chlordane

NotoedresN. cati- ears, head and back of the neck of catN. cati var. cuniculi- ear of rabbitN. muris- rats

Spines are absent Dorsal anus is subterminal compared to Sarcoptes which is terminal The dorsal and subterminal body more circular than Sarcoptes Causes ear mange Lesions occur chiefly on the ears and back of neck but may extend to the face, foot and hind paw or even the

whole body in kittens The skin becomes markedly thickened and wrinkled

CnemidocoptesCnemidocoptes gallinae “depluming itch mite” of fowl

Mites burrow deep into the skin alongside the shafts of the feathers and cause an itching, inflammatory condition Birds pull out the feathers which break off readily

C. mutans “scaly leg mite” Common in the Phils. Mites burrow beneath the scales from the ground Inflammation with exudate that hardens on the surface and displaces the scales; this is accompanied by

keratinization which renders the scales “powdery” in appearanceC. pilae “scaly leg mite”

Occurs in caged birds like parakeets and lovebirds Beaks become deformed, scaly, and crusty

Treatment:1. 0.15% neguvon dip2. 0.5% malathion dip3. 0.5% chlordane4. for Cnemidocoptens mutans, dip legs in kerosene mixed in oil, then apply 10% sulfur ointment

PSOROPTIDAE

General Characteristics:1. Do not burrow into the skin and are parasitic in its surface layers causing the formation of a thick, heavy scab

rather than a thickened skin

Psoroptes “scab mites”P. ovis- sheep,most common hostP. equi- horseP. natalensis- cattle, buffalo, carabaoP. cuniculi- ears of rabbit, goat, sheep, horse

Pathogenesis:Mite punctures epidermis and suck lymph stimulating an inflammatory response serum exudes on to the surface

and coagulates, forming crust wool becomes loose and fall out, or it is pulled out by the sheep in biting and scratching the lesion which is markedly pruritic

Life cycle:Eggs are laid on the skin at the edge of the lesion eggs hatch in 1-3 days and the larvae feed molt into nymph

after 2-3 days adult develops after 3-4 daysPubescent female appear 5 ½ days after hatchingLife span of female: 30-40 days and lay 5 eggs daily with a total of 90 or more

Chorioptes

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C. bovis – leg of cattleC. equi – fetlock of horseC. ovis – pastern of sheepC. caprae – leg of goatC. cuniculi – ear of rabbit

“Foot Mange” or “Itchy Leg” that results from rubbing, scratching, leg biting, and kicking Life cycle completed in 3 weeks; resembles Psoroptes

OtodectesO. cynotis

Ear mite of wild and domestic carnivores causing “otodectic mange”, parasitic otitis” or “otoacariasis” Dogs may show head shaking which may lead to development of hematoma Infection may extend to the middle and inner ear (aggravated by bacterial infection) then in the brain and show

“epileptiform fit”, animal shows circling

Treatment:1. Cerumite2. Ivermectin3. 20% benzyl benzoate

ANALGESIDAE Megninia cubitalis – feather and skin of chicken and turkeys; common in the PhilippinesM. velata – feathers of ducksM. columbae – PigeonMegninia sp. – turkey

DERMOGLYPHIDAE

Pterolichus obtusus Feather and skin of chickens Very common in the Philippines Causes feather pulling

CLASS PENTASTOMIDA

General characteristics:1. Small group of arthropods allied to mites and annelids2. Most are internal parasites of the respiratory organ of vertebrates3. Adults live in the respiratory organs; larvae, and nymphs are free or encysted in the viscera of mammals, birds,

reptiles and fishes4. Cephalothorax is broad and merges into the tampering abdomen5. Anterior end is thick, with ventral surface flat and armed with 2 pairs of retractile, chitinous hook on either side of

the suctorial mouth6. Cuticle is striated or deeply ringed

Life cycle in generalLarvated egg is laid with 2-3 pairs of rudimentary clawed legs ingestion by the intermediate host eggs hatch in

the intestine passes through the intestinal wall circulation encyst on visceral organs molts and lose the legs during the process nymph (ineffective to the final host) ingestion of infected or intermediate host of infected organ

POROCEPHALIDAE

LinguatulaL. serrata “tongue worm”

Adults are found in the nasal passages of dogs, fox, horse, sheep, goat and rarely man Larva and encysted nymphs are found in herbivores Tongue shape; convex dorsally and flat ventrally Female 8-10cm length with about 90 annulations

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Life cycle:Larvated eggs discharged in nasal secretions or swallowed and passed out the feces swallowed by herbivores

(rabbit, ruminant, equine) in contaminated food and water larvae penetrate intestinal wall circulation mesenteric lymph nodes, lung, liver, kidney nymph (molts 9 times before they become infective in 6 months) dogs eat infected organ nymph migrate from the stomach to the pharynx nasal passagesEncysted nymphs may live for several yearsAdults live for about 15 months

Pathogenesis

1. Causes severe irritation in the final host2. Signs include sneezing, coughing, dyspnea, snoring, ribbing its nose with forefeet, often blood stained nasal

discharge and restlessness

PorocephalusP. armillatusP. moniliformis

Adults in the nasal cavity, trachea, and lungs of snakes, crocodiles, lizards and other reptiles Nymphs are found in the mesenteric lymph nodes, liver, kidney, etc of wild and domestic animals and man Body has a beaded appearance

CLASS CRUSTACEA

SubclassCopepoda (crayfish) – of veterinary importanceDecapoda (lobsters, crabs, shrimps)

General characteristics of Copepods:1. Most are free living, only few are parasitic2. Body is covered by a rigid or semi-rigid exoskeleton called carapace3. With jointed appendages4. Only copepods are of veterinary importance by serving as intermediate host to the some helminths5. Eggs hatch into larvae called nauplius

Ergasilus sp Found in gills of freshwater fishes Heavy infection leads to retarded sexual maturity and growth, impaired respiration and death

Salmincola sp Found in gills and fins of salmonids Clinical signs similar to Ergasilus sp

Achteres spp Gills of freshwater fish Clinical signs similar to Ergasilus sp

Lernaea sp “Anchor Worm” Anchor parasites of freshwater fishes; the head (cephalic horn) is buried in host’s tissue Destroy scales and cause ulcer at the site of penetration leading to attack of other infections (viral, bacterial,

fungal) Causes growth retardation, sluggish movement and death

Argulus sp “Fish Lice” Occurs in freshwater fishes Puncture the skin, feed on blood, and inject cytolytic toxins Cause erratic swimming “flashing” and poor growth

Cyclops – intermediate host of dog pseudophyllidean tapewormDiaptomus – intermediate host of dog pseudophyllidean tapeworm

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Control:1. Introduction of parasite free fish2. Destruction of infected fish3. Filtration of water4. Dry ponds before restocking5. Chemicals for killing several larval stages

a. 0.85% calcium chlorideb. 0.2% copper sulfatec. 1.7% magnesium sulfated. 0.5 ppm Dipterexe. 0.25 ppm Malathion weekly for 5 weeksf. 30-100 ppm Pyrethrumg. Dip in 2000 ppm Lysol for 5-10 seconds for individual fish

INJURIOUS NON-PARASITIC ARTHROPODS

Ways of eliciting injury to host:1. Piercing or biting – inject poisonous or irritating substances into a wound made by their mouthparts or poison

claws e.g. spiders and centipedes2. Stinging – inject a poison by means of a sting situated at the tip of the abdomen e.g. bees and wasps3. Nettling – scales or hairs with irritating properties e.g. caterpillars4. Cryptotoxic – with irritant or poisonous body fluids e.g. blister beetles

PIERCING SPECIES:

1. Millipedes (order Diplopoda) Has 2 pairs of legs per body segment Normally feeds on decaying plant matter Non-poisonous in general Some large species may inject pungent fluid when they are irritated which can cause dermatitis and blindness

in birds e.g. Julius terrestris (1 inch long)

2. Centipedes (order Chilopoda) With 1 pair of legs per body segment They are carnivorous (insect and small animals and they use their claws to stun their prey Smaller forms cause local irritation Large forms (Scolopendra gigantean) could cause lymphangitis, fever, vomiting, headache and even death in

man

STINGING SPECIES:

1. Order Hymenoptera The sting is present only in female being a modified ovipositor, the poison is located at the tip of the abdomen The sting consist of a pair of serrated darts connected to a poison sac or glands Stings are usually due to bumble bees, wasp (putakti), hornets, honey bees It has a poison reservoir which can secrete both alkaline and acid substance (formic acid) The sting of the bee is introduced as the tip of the abdomen with the whole poison apparatus breaks off and

remains in wound and the muscle continue contraction by reflex thus forcing the poison out of the sac into the tissue for some time.

The bite results to local edema and/or necrosis The pain is attributed to the poison introduced Systematic effects which may result to death may occur 500 stings could kill an adult animal or an extremely sensitive individual

2. Ants Seldom use their stings though most of them have Poison (formic acid) is injected after biting Fire ants or “hantik” (Solenopsis sp) could kill an animal

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3. Order Scorpioneidea “Scorpions” “Alakdan”Centruroides suffusesC. sculpturatus Abdomen elongated with a broad anterior part and an attenuated posterior part Posterior end bears the hooked sting After a “courtship dance” and the mating act, the female devours the male Females are viviparous The offspring are carried on top of the female for 12 days The venom glands are located at the post abdominal segment Scorpions attack by holding the victim by its claws and thrusting the entire abdomen dorsally and forward Poison is cryptotoxic or neurotoxic Generalized symptoms may occur and death due to asphyxia may result

4. Order Araneidea “Spiders” The poison is located at the cephalothorax which open through pores at the tip of the chelicerae Poison is used to kill or paralyze small animals like flies, mosquito etc and suck body fluids Most spiders are non-poisonous and do not bite

Lycos tarantula “Tarantula” “Wolf Spider” caused “Spider Scare” in Italy during the 17th century The bites allegedly produced “Tarantism” which is characterized by hysterical madness and could only be

cured by performing a wild, frenzied dance called “Tarantella”

Latrodectus mactans “Black Widow” “Hour Glass Spider” Measures up to 3cm including the legs Inhabits protected shaded places Most pathogenic species Glossy black in color with a red “Hour Glass” spot on the ventral side of the abdomen Only females are dangerous Females ensnare and eat the male after mating but the males are spared if food is immediately available Venom is chiefly a neurotoxin Muscular spasms and signs of shock occur which may be followed by death but in most cases, signs

disappear without treatment in 2-3days Frequent bites are in the buttocks and penis

NETTLING/URTICATING SPECIES

o Hairy caterpillars “Higad” of some butterflies and moths produce irritation by means of their poison glands which are located at the base of the hair and remains on the skin in contact

o Spanish fly beetle – adults are plant feeders; contains cantharidino Korean bug/beetle are said to have narcotic, aphrodisiac and excitatory effect

Treatment of insect bites and stings

1. Centipede bites – apply ammonia and local anaesthesia2. Bee and Wasp Stings – remove sting, pack with ice then apply baking soda; give antihistamines, steroid or

epinephrine if allergic reaction is evident3. Scorpion sting – apply tourniquet, loosen every 15-30 minutes, then apply ice pack4. Spider bite – administer 10% calcium gluconate then allow rest5. Urticating Insects – remove hairs and scales by applying adhesive tape, wash area with mild antiseptic, then

apply calamine lotion; give antihistamine in severe cases

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