Class Arachnida

Order Scorpiones

Order Pedipalpi

Order Solifugae

Order

Order Aranei

Order Acari

Pseudoscorpiones Order

Opiliones

1500 extant species in 170 genera and, depending on the authority, between 13 and 20 families (depending on the authority),

pedipalps

metasoma

In appearance the most are characterized by large palps with claws and articulates a flexible metasoma (tail) with a poisonous apparatus at the end

Scorpion sting

If you are stung by any scorpion, you should:

Wash the area of the scorpion sting with soap and water.

Apply a cool compress on the area of

the scorpion sting. Ice may be applied to the sting location for 10 minutes.

If stung on a limb (arm or leg) elevate the limb to or above heart level.

If you develop symptoms such as numbness or tingling in your extremities or face, blurred vision, muscle

twitching, or random eye movements, go to the nearest emergency room .

If possible without further risk, capture and take the scorpion with you.

Keep your tetanus shots and boosters current.

Very few people die from scorpion stings! Scorpion stings are most dangerous to the very young and the very old. Pets are also at risk.

Order Araneae

Spider bite - to enter into the body of the victim of poison with chelicerae. Of the approximately 40,000 species of spiders living on the Earth only 10-12 spiders may cause significant harm to human health or kill him. Symptoms of a poisonous spider bite can be of three kinds:

action of the venom

allergic reaction to poison

infection is made through a wound.

Chelicerae and palps

Cheiracanthium punctorium.

Mouthparts of spider : 1 - the final segment of the chelicerae unguiculate, 2 - the main segment of the chelicerae, 3 - pedipalps

The brown recluse spider, Loxosceles reclusa

Order Araneae

Loxosceles reclusa

The bite of brown recluse

The bite of brown recluse

The bite of brown recluse

after 5 days

after 6 days

after 10 days

Order Acari

Trombidiiformes

Trombiculidae gen. sp.

Trombiculidae

Commonly called trombiculid mites (also called berry bugs, harvest mites, red bugs, scrub-itch mites, and, in their larval stage, chiggers). Trombiculidae typically live in forests and grasslands and are also found in low, damp areas with rank vegetation such as woodlands, berry bushes, orchards, along lakes edges and streams, but also in drier places where vegetation is low such as lawns, golf courses, and parks.

They are most numerous in early summer when grass, weeds and other vegetation are best developed. In their larval stage they attach to various animals, including humans, and feed on skin, often causing itching. These relatives of ticks are nearly microscopic, measuring 0.4 mm, and have a chrome-orange coloration. A common species of harvest mite in north America is Trombicula alfreddugesi; in Europe the most prevalent harvest mite is Trombicula autumnalis. The trombiculid mites life cycle includes stages of egg, larva, nymph, and adult. The larvae feed on the skin cells, but not blood, of animals, including humans. The six-legged parasitic larva feeds on a large range of animals including humans, rabbits, toads, box turtles, quail, and even some insects. After crawling onto their host, they inject digestive enzymes into the skin that break down skin cells. They do not actually "bite," but instead form a hole in the skin called a stylostome and chew up tiny parts of the inner skin, thus causing severe irritation and swelling. The severe itching

is accompanied by red pimple-like bumps (papules) and skin rash or lesions on sun-exposed areas. In humans, itching usually occurs after the larvae detach from the skin.

After feeding on their hosts, the larvae drop to the ground and moult to become 8 legged nymphs , which then mature into adults and are harmless to humans. In the post larval stages, they are not parasitic and feed on plant materials. The females lay 3–8 eggs, usually on a leaf or under the roots of a plant, and die by autumn.

the Leptotrombidium deliense are considered a dangerous pest in East Asia and the South Pacific because they often carry Orientia tsutsugamushi, the tiny bacterium that causes scrub typhus, which is known alternatively as the Japanese river disease, scrub disease, or tsutsugamushi. The mites are infected by the Rickettsia passed down from parent to offspring before eggs are laid in a process called

transovarial transmission. Symptoms of scrub typhus in humans include fever, headache, muscle pain, cough, and gastrointestinal symptoms

Cheyletidae

Cheyletid mites are mostly free - living predators that commonly feed on other mites and small arthropods in stored products. Occasionally they cause pruritic dermatitis in people handling infested grains and other dried plant materials. The most common cheyletid found in stored products is Cheyletus eruditus. This cosmopolitan species has been used commercially as a biological control agent to reduce the numbers of grain mites, notably

Acarus siro and Lepidoglyphus destructor, in granaries and agricultural warehouses.

Cheyletus eruditus

Pyemotidae

Pyemotid mites are ectoparasites of insects that typically attack the larval stage of moths, beetles, and hymenopterans. A few species commonly occur in dried, insectinfested plant products such as hay, straw, and grains. On contact with humans and other animals, these mites cause intense itching when they pierce the skin with their stylet-like chelicerae and inject a toxin produced in their salivary glands. It is a very potent neurotoxin which they use to immobilize their insect prey, enabling them to paralyze insects 150,000 times their size.The most important species affecting humans is Pyemotes tritici. It is variously known as the straw itch mite, hay itch mite, and grain itch mite, depending on the plant material with which it is associated. Exposure to P. tritici represents an

occupational hazard for agricultural workers, sales and stock personnel in farmsupply stores, and other individuals in the arts and crafts field who handle wheat, hay, and straw. People handling infested materials usually develop multiple sldn lesions in the form ofpapules or papulovesicles, accompanied by intense itching. Heavily infested, or sensitized, individuals may experience other symptoms, including headache, fever, nausea,vomiting, diarrhea, and asthma.

Straw itch mite, Pyemotes tritici

(Pyemotidae), gravid female, dorsal view.

Demodicidae

Members of this family are called follicle mites. They are extremely tiny, elongate, annulate mites with very short, three-segmented legs. They lack body

setae and possess a pair of tiny, needle-like chelicerae which are used to pierce dermal cells, on which the mites feed. Their minute size and strong reduction of most of the external features represent adaptations for living in the close confines of hair follicles and associated ducts and glands.

Two species of Demodex infect humans.

Demodex folliculorum occurs primarily in hair follicles, whereas D. brevis is generally found in the sebaceous glands that open via ducts into the hair follicles. Both species may infest the same host, appearing together in samples taken from a given individual. 90-100% of all humans apparently harbor follicle mites. Human follicle mites tend to occur primarily in the regions of the forehead, eyelids, and nose. In most cases they cause no apparent harm and go virtually unnoticed but in certain cases (usually related to a suppressed immune system, caused by stress or illness) mite populations can dramatically increase, resulting in a condition known as emodicosis or Demodex mite bite, characterised by

itching, inflammation and other skin disorders. Blepharitis (inflammation of the eyelids) can also be caused by Demodex mites.

Acaridae

Acarid mites infest a wide range of stored materials such as grains, milk products, dried fruits, straw, and animal hides in both households and commercial storage facilities. Their numbers can build rapidly, especially when the infested materials are damp enough to support the growth of fungi on which they typically feed. Dermatitis occurs when the mites pierce the skin in attempts to feed or obtain moisture.

The most important acarid mite in stored products is Acarus siro, a species found throughout most of the world. It is particularly a pest of processed cereal products (e.g., flour), rather than whole grains or hay.

Acarus siro – the flour mite

HOUSE-DUST MiTES:

Pyroglyphidae

The most widespread pyroglyphid species that causes house-dust allergy is the European house-dust mite (Dermatophagoides pteronyssinus), which thrives in floor dust and the surface dust of mattresses. It is regarded as the most frequently encountered house-dust mite, occurring especially in humid coastal areas of western Europe and

North America. This was the first mite to be identified as a cause of house-dust allergy in 1966, shortly after the genus Dermatophagoides was first linked to house dust and bronchial asthma.

House-dust mite

Dermatophagoides pteronyssinus

Sarcoptidae: Sarcoptes scabiei

Sarcoptes scabiei

Sarcoptes scabiei var. hominis, the human itch mite, is in the arthropod class Arachnida, subclass Acari, family Sarcoptidae. The mites burrow into the upper layer of the skin but never below the stratum corneum. The burrows appear as tiny raised serpentine lines that are grayish or skin-colored and can be a centimeter or more in length. Other races of scabies mites may cause infestations in other mammals, such as domestic cats, dogs, pigs, and

horses. It should be noted that races of mites found on other animals may cause a self-limited infestation in humans with temporary itching due to dermatitis; however they do not multiply on the human host.

Scabies

a contagious skin infection caused by the mite Sarcoptes scabiei, characterized by intense itching, inflammation, and the formation of vesicles and pustules

Parasitoformes• Gamasoidea

Dermanyssius gallinae

Гамазовые клещи (Gamasoidea), группа клещей отряда Parasitiformes. Около 20 семейств. Туловище Г. к. овальное или продолговатое (0,3—4 мм), покрыто щитками (цельный или двойной спинной и несколько брюшных); на теле многочисленные щетинки, постоянные по числу и положению. Ноги шестичлениковые, с коготками и присоской. Ротовые органы грызуще- или колюще-сосущие. Хелицеры с клешнями или игловидные, выдвигаются из трубчатого основания — сросшихся тазиков педипальп. Дышат Г. к. с помощью трахей, открывающихся стигмами по бокам тела. Г. к. откладывают яйца, многие живородящи; шестиногая личинка, линяя, превращается в восьминогую нимфу первую, нимфу вторую и во взрослого клеща. Развитие непродолжительное: Г. к. за сезон могут давать десятки поколений. Большинство Г. к. — хищники; обитают в почве, лесной подстилке, навозе, где питаются мелкими членистоногими, нематодами и т. п. Некоторые виды расселяются на навозных и трупоядных насекомых. Представители ряда семейств (Laelaptidae, Macronyssidae, Dermanyssidae и др.) перешли к паразитизму и кровососанию на пресмыкающихся, птицах и млекопитающих. Способы паразитирования разнообразны (формы, живущие в гнёздах животных-хозяев или постоянно на их теле, в дыхательных органах и др.). Некоторые виды нападают на человека. Укусы Г. к., например куриного клеща (Dermanyssus gallinae), в массе размножающегося в птичниках, вызывают острый дерматит. Г. к. переносят возбудителей инфекционных заболеваний. Крысиный клещ (Macronyssus bacoti), живущий в крысиных норах и трещинах стен строений, может передавать человеку через укус крысиный сыпной тиф и чуму. Мышиный клещ (Allodermanyssus sanguineus) передаёт лихорадочное заболевание — везикулёзный риккетсиоз. Клещи рода Hirstionyssus, по-видимому, способны распространять туляремию среди грызунов в природных очагах этой инфекции.

Tick-borne relapsing fever:

Ornithodorus papillipes

• Argasidae

Ornithodorus cf. papillipes

Tick-borne Relapsing Fever

Other relapsing infections are acquired from other Borrelia species, such as Borrelia hermsii or , which can be spread from rodents, and serve as a reservoir for the infection, via a tick vector. Borrelia hermsii and Borrelia recurrentis cause very similar diseases although the disease associated with Borrelia hermsii has more relapses and is responsible for more fatalities, while the disease caused by B. recurrentis has longer febrile and afebrile intervals and a longer incubation period.

Tick-borne relapsing fever is found primarily in Africa, Spain, Saudi Arabia, Asia, and certain areas in the Western U.S. and Canada. It is Borrelia duttoni transmitted by the soft-bodied African tick Ornithodoros moubata that is responsible for the relapsing fever found in Central, East and southern Africa.

Diagnosis

Most people who are infected get sick around 5-15 days after they are bitten by the tick. The symptoms may include a sudden fever, chills, headaches, and muscle or joint aches, and nausea; a rash may also occur. These symptoms continue for 2-9 days, then disappear. This

cycle may continue for several weeks if the person is not treated.[5] Relapsing Fever is easily treated with 1-2 weeks of antibiotics. Most people improve within 24 hours of starting antibiotics. Complications and death due to relapsing fever are rare.

Ixodidae

• Ixodes ricinus

Ixodes persulcatus: Tick-borne encephalitis

Hyalomma

plumbeum

Adults of Dermatobia hominis are free-living flies . Adults capture blood-sucking arthropods (such as mosquitoes) and lay eggs on their bodies, using a glue-like substance for adherence . Bot fly larvae develop within the eggs, but remain on the vector until it takes a blood meal from a mammalian or avian

host. Newly-emerged bot fly larvae then penetrate the host's tissue . The larvae feed in a subdermal cavity for 5-10 weeks, breathing through a hole in the host's skin. Mature larvae drop to the ground and pupate in the environment. Larvae tend to leave their host during the night and early morning, probably to avoid desiccation. After approximately one month, the adults emerge to mate and repeat the cycle. Other genera of myiasis-causing flies (including Cochliomyia, Cuterebra, and Wohlfahrtia) have a more direct life cycle, where the adult flies lay their eggs directly in, or in the vicinity of, wounds on the host

. In Cochliomyia and Wohlfahrtia infestations, larvae feed in the host for about a week, and may migrate from the subdermis to other tissues in the body, often causing extreme damage in the process.

Geographic Distribution:

Dermatobia hominis and C. hominovorax are Neotropical species, ranging from Mexico into South America. The Congo floor maggot (Auchmeromyia luteola) and Cordylobia anthropophaga are distributed in Africa south of the Sahara. Wohlfahrtia magnifica occurs in the Mediterranean basin, Near East, and Central and Eastern Europe; W. vigil occurs in northern United States and Canada. Cuterebra species are found in the New World. Oestrus ovis is found throughout the world in areas where sheep are tended.

Cochliomyia hominovorax.

Clinical Features:

Infestations with D. hominis are often characterized by cutaneous swellings on the body or scalp that may produce discharges and be painful. Death is rare, but there have been instances of cerebral myiasis in children where larvae enter the brain. Infestations with C. hominovorax, which causes wound myiasis, can be more serious, as this species may travel through living tissue in the body and not stay subdermal like most of the other species of flies that cause

myiasis. Death has occurred with severe infestations of C. hominovorax. Secondary bacterial infections may also

occur. Oestrus ovis has been known to cause a condition called ophthalmomyiasis, which is infection of the eye with fly larvae. Flies in the genera Phormia and Phaenicia cause facultative myiasis, where adult flies lay their eggs in pre-existing, festering wounds and do not invade healthy, living tissue.