Post on 06-Sep-2018
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LEPIDOPTERA: butterflies and moths 175,000 species
egg larva pupa adult Lep. Larva = caterpillar Many agricultural pests Variable feeding habits
ECB Larvae are borers and feed
on over 200 plant species
including corn, pepper,
potatoes, beans and cotton.
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Native to Eurasia, it was accidentally introduced in to the US about 100 years ago.
Is currently the main pest of maize, Zea mays, throughout the world that can cause an excess of $1 billion a year in damages and control costs.
Corn damage is in the ears and stalks, reducing the overall yield.
Burrowing can cause stalk breakage.
Tunneling disrupts water and nutrient transport and provides site for infection.
Illustration by Arthur Cushman. Property of the Smithsonian Institution Dept of Entomology.
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Larvae overwinters in stems and produces 2‐3 generations per year, but 3rd generation does not cause significant damage.
2nd generation emerges in late July to early August.
% yield loss differs depending on the plant growth stage at the time the damage occurs. Moisture stress increases pest susceptibility significantly.
Identification: adult, approx. 15mm long
Lepidoptera:
Crambidae: Pyraustinae
MaleFemale
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Final identification: adult genitalia dissections
Female Male
Identification: larvae ‐ 5 instars
Full‐grown larvae are about 1 in. long, grey or tan with small brown spots on each segment. The head is black or dark brown.
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BT Maize: 85% of the maize crop grown in the US is GM
Transgenic maize with a modified genome to include a gene for Bacillus thuringiensis toxin which affects the corn borer larvae (82% effective).
Downsides:
beneficial insects may be affected by these toxins
increased probability of evolution of pest resistance
Biocontrol methods: Trichogramma spp. (Hymenoptera): egg parasitoid wasp
Lydella thompsoni (Diptera): larval parasitoid fly
Beauveria bassiana (Fungi): entomopathogenic fungus Kills up to 84% of larvae
Nosema purausta (Protozoa) Infects all life stages, results in reduced vitality
Trichogramma brassicae Lydella thompsoni Beauveria bassiana
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Other pest management strategies: Mating disruption using sex pheromones
The push‐pull strategy: repelling pests from crops and luring them towards attractive trap plants
Early harvest
Stalk shredding, plowing, grazing, or burning stalks.
Survey methods: Pheromone Traps
Contain a chemical that mimics female mating signal
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Survey methods:
Light traps
Adults are active at night
15 watt UV lamp light source
Downside: not specific, requires
lots of sorting
Survey methods: Field Scouting: look for damage such as broken stalks of corn and entry holes. Early infestation isn’t obvious.
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Chemical treatments: granules or spray insecticides Mortality of newly hatched larvae is very high. If possible, avoid making a treatment decision until larvae have aged to second instar or older but are still in the plant whorl and all infested plants show clear evidence of whorl feeding.
Borers still in the whorl can be controlled chemically. If all larvae have left the whorl, it is too late to attempt control.
Ordering supplies: Light Traps:
Gempler’s Black Light Trap Kit – 15‐watt 110‐AC Power Source. Item No: RAB11. 1‐800‐382‐8473
Pheromone Traps: (Scentry Wing traps with Iowa Strain ECB lure) Ecogen, Inc., Scentry Division, 2005 Cabot Blvd. West, Langhorne PA 19047 Phone: 1‐800‐220‐3326, or (215)‐757‐1590.
Great Lakes IPM, 10220 Church Road NE, Vestaburg, MI 48891 Phone: (517) 268‐5693
European Corn Borer Phenology and Management Model: Send orders with payment (payable to University of Nebraska) to Bob Wright, University of Nebraska South Central Research & Extension Center. Box 66, Clay Center, NE, 68933‐0066. Or, contact Bob at (402) 762‐4439. Specify 3 1/2 or 5 1/4" disk size. $71.23 (includes sales tax, shipping and handling)
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Biology: Termites There are more than 2600 described species of termites.
Termites are related to cockroaches.
Termites digest wood using symbiotic protozoa (LT), bacteria and/or fungi (HT) to break cellulose to simple digestible sugars.
Categorized (by feeding habits) in to drywood, dampwood and subterranean termite groups. Drywood termites feed on sound dry wood and don’t need extra moisture source.
Dampwood termites infest damp decaying wood.
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Biology: Termites are eusocial: caste differentiation
Reproductive, soldier , & worker
Undifferentiated, <3rd instars are called nymphs or larva
hemimetabolous
Biology: Subterranean termites
80% of economically important
species of termites are subterranean
Forage in soil for food and build colonies larger than arboreal termites. Foraging galleries can extend up to 100m
to establish satellite nests.
Attack moist wood and need continuous supply of moisture Can construct above‐ground nests
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Native to East Asia, it became established in many places world wide in the 20th century. It was introduced in to the continental US in 1957.
First record in Hawaii in 1907
It is believed that FT’s main
transportation was by wooden
ships, ship palettes, crates and
wood packing material.
The Formosan termite is now found in 15 states, including Texas. First TX record was at a shipyard in Houston in 1965
Spread across state lines has been via infested wood, soil or plant material
Projected to spread northward in the US to about 35°latitude, approximately the border between Mississippi and Tennessee.
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Distribution:
Distribution: TX The first infestations of
Formosan termites in TX were
discovered in 1965 around the
Houston Ship Channel in
Pasadena, Harris Co.
Since then, they have been
detected in 31 counties in TX,
with more being added each
year.
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Very destructive The annual costs associated with damage repair and control of the FST are estimated to exceed $1b in the US.
Consume wood at a very rapid rate This is due to the very large colony size, in the millions as compared to thousands of individuals in other species
http://urbanentomology.tamu.edu/wdi/termites/formosan.html
Railroad tie damage House damage
Signs of infestation: Signs of termite infestation include mud (“shelter”) tubes filled with termites, dull or hollow damaged wood filled with soil deposits, and shed wings or other insect material.
Although considered subterranean, Formosan Termites often construct nests within the structure they infest above ground.
Formosan termite nest under the floor
Formosan termite mud tubes
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Case example: New Orleans, LA
“Damage caused by FSTs to a window sill of the Southern Regional Research Center Library . The colony nest was located two floors below in the soil, but workers entered the building through mud shelter tubes that they constructed through the hollow brick walls. The damage went unnoticed until moisture from foraging galleries by the termites caused the paint to blister. Much of the wood had been consumed by the termites before they were detected.”http://www.forestryimages.org/browse/detail.cfm?imgnum=1324025
Factors influencing Formosan Termite colony survival:
Temperature The optimum for FT is 82°F
Substrate moisture (wood, soil)
Termites have a very soft cuticle and are very susceptible to desiccation. Air moisture isn’t enough for subterranean termites
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Termiticides:
Many of the early termiticides like DDT, aldrin, dieldrin, heptachlor and BHC were banned for their toxicity.
Current method of controlling STs involves
application of liquid insecticides in the subslab soil.
The alternative are baits which have high labor application costs but are more ecofriendly.
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“Economic” fruit fly
Can cause economic losses both locally and nationally
Of 4,352 species, only about 1.7% are pests
But they are among the most costly pests
Wide host range
Wide climatic range
High reproductive capacity
Early detection through vigorous
monitoring
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Native habitat: Widespread throughout the West Indies, being reported from
the Bahamas, Cuba, Dominican Republic, Haiti, Jamaica, and Puerto Rico
The latest introduction was in to FL in
1965, after which it quickly spread
throughout the state. There is constant gene flow or migration
between Florida and the Caribbean
Adults have also been trapped in CA
several times, isolated incidents.
Hosts: nearly 100, including citrus, guavas, cherry, peach and mango The rapid spread of the pest in FL was attributed to the presence of
many of the fly's host plant species, which includes at least 80 different fruit and vegetable hosts commonly found in Florida
Infests only mature or overripe fruit
Life cycle lasts about 6 weeks
Larvae are morphologically indistinct
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Wings have color pattern
Sc vein is bent at 90°
CuP cell extended
Females with a distinct ovipositor
A. suspensa
Body 12‐14mm long
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Mexican fruit flyAnastrepha ludens
Mediterranean fruit flyCeratitis capitata
Damage:
Not significant within its normal range of distribution
In FL, only very ripe citrus has been attacked
Lots of concern regarding how the strain will change in the new environment.
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Survey methods:
Anastrepha adults need protein for ovary development. Many lures are based on odors released from hydrolyzed proteins, like ammonia and hydrolyzed torula yeast.
No single bait currently exists; a combination of traps and lures is needed.
Best method is to cut & inspectvery ripe fruit visually
Management:
Limited spraying of groves & adjacent areas with pesticides
Attempts are being made to develop an IPM approach using biocontrol agent (larval parasitoid) and
releasing sterile flies (SIT)
Diachasmimorpha longicaudata(Braconidae)