What is the effect of bats and purple martins on mosquito populations according to the material?

• A. There is no basis for claimed suppression of mosquito biting activity by bats or purple martins. Their predation is insufficient to significantly reduce mosquito densities
• B. They significantly reduce mosquito densities
• C. They mainly reduce egg production
• D. They attract more mosquitoes

Answer: (A)

Predation by bats and purple martins does not meaningfully cut mosquito numbers. The material notes there is no basis for claims that these predators suppress mosquito biting activity, because their overall impact is too small to significantly reduce mosquito densities. Mosquito populations grow rapidly and reproduce in large numbers, so the few insects eaten by these predators don’t substantially shift the population. Additionally, predation by generalist predators isn’t targeted to the stages or times that would most reduce biting risk. So, even though they eat some mosquitoes, their effect on overall densities is not enough to rely on for control. The other ideas—that they significantly reduce densities, mainly reduce egg production, or attract more mosquitoes—aren’t supported by the material.