What is the purpose of parity sampling in wild mosquito populations?

• A. Dissecting female mosquitoes to assess ovarian follicle development stage to estimate age structure and potential for transmission.
• B. Measuring the number of eggs laid per female.
• C. Testing for insecticide resistance in larvae.
• D. Counting the number of male mosquitoes.

Answer: (B)

Parity sampling focuses on whether a female mosquito has completed an egg-laying cycle, which tells us about her age and her capacity to contribute to transmission. In practice, researchers dissect the ovaries and look at follicle development to classify females as nulliparous (have not yet laid eggs) or parous (have laid eggs before). This information lets us estimate the age structure of the population and, because older females are more likely to have become infectious after the pathogen’s incubation period, infer the population’s potential for transmission.

Counting eggs laid per female measures fecundity—the reproductive output of individuals—rather than whether a female has previously laid eggs. Parity status hinges on prior egg-laying history (parous vs. nulliparous) inferred from ovarian development, not on total eggs produced in a single cycle. The other choices describe different aspects (like male counts or insecticide resistance testing) and aren’t used to assess parity.