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These 10 free BCE questions are organized by exam domain, so you can see how each part of the Board Certified Entomologist blueprint is tested. Reveal the answer and explanation under each question.
After West Nile virus cases occur in people and horses, a planning team proposes making infected horses the main focus of efforts to interrupt mosquito infection. What feature of the transmission cycle most directly challenges that proposal?
Correct answer: A - Birds sustain amplification; humans and horses usually develop too little viremia to infect mosquitoes.
A nursery treats foliage-feeding larvae with Bacillus thuringiensis subsp. kurstaki, but feeding continues. Examination of several intact larvae reveals three pairs of jointed thoracic legs and seven pairs of abdominal prolegs without crochets. What diagnosis best reconciles the specimens with the poor treatment response?
Correct answer: C - Sawfly larvae, outside the target range of this caterpillar-active Bt subspecies.
Cattle repeatedly stamp their feet as house-fly-sized insects take brief blood meals from their lower legs. A captured fly has a rigid proboscis projecting forward from its head. Which identification and breeding-site pairing should guide the search for immature stages?
Correct answer: B - Stable fly; wet, fermenting hay mixed with manure near feeding areas.
Small, hard pellets repeatedly appear below tiny openings in an interior window frame. Under magnification, the pellets have six concave sides. The affected wood is dry, and no soil connection is visible. Taken together, these findings are most consistent with damage by:
Correct answer: A - Drywood termites inhabiting the wood without requiring a soil connection.
Before commitment to pupation, final-instar larvae of a holometabolous insect receive an experimental compound. They undergo another larval molt, while untreated larvae pupate. Normal ecdysteroid pulses occur in both groups. Which endocrine action accounts for retention of the larval form?
Correct answer: A - Maintaining juvenile-hormone activity during an ecdysteroid pulse.
Two cohorts of the same insect species stop developing. Cohort X, previously exposed to short days, remains arrested for a time after transfer to otherwise favorable conditions. Cohort Y was chilled without a short-day cue and resumes development promptly when warmed. How should these arrests be distinguished?
Correct answer: C - X shows diapause; Y shows quiescence.
Representative scouting of an R3 soybean field finds 290 aphids per plant, down from 420 four days earlier; 90% of plants are infested, and predators and aphid mummies are abundant. The regional treatment rule requires all three conditions: more than 250 aphids per plant, more than 80% of plants infested, and an increasing population. What should the consultant recommend?
Correct answer: D - Continue frequent scouting and conserve natural enemies while the population is declining.
During one surveillance week, a mosquito-control district tests 1,200 female mosquitoes of one species from one surveillance area. They are divided into 60 pools of 20; six pools test positive for West Nile virus. Individual mosquitoes are not retested. Which entry correctly reports the minimum infection rate and its limitation?
Correct answer: B - 5 per 1,000 mosquitoes; positive pools may contain more than one infected individual.
In replicated forced-contact bioassays, permethrin kills 25% of a field cockroach population and 98% of a susceptible reference population. Pretreatment with piperonyl butoxide raises mortality in the field population to 92%; the synergist alone causes negligible mortality. Which resistance mechanism is most strongly supported by the large response to the synergist?
Correct answer: D - Enhanced detoxification by enzymes inhibited by the synergist.
Thirty-six hours after a pesticide application ends on a U.S. farm covered by the Worker Protection Standard, a trained crop scout is ready to inspect the treated crop. The applicable label specifies a 24-hour restricted-entry interval and a 7-day preharvest interval. All other entry requirements are satisfied, and no additional restriction applies. What work may proceed today?
Correct answer: D - Scouting, but not harvest; the restricted-entry and preharvest intervals govern different activities.
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