Which surveillance method uses a tongue depressor wrapped in paper towel emerged in a one-pint, black jar that has been half-filled with water to collect eggs?

• A. Larva collection site
• B. Ovitrap for mosquito eggs
• C. Artificial resting site for adult mosquitoes
• D. Collection device for mosquitoes in the pupal stage

Answer: (B)

Ovitraps are a surveillance method designed to monitor mosquito egg-laying activity. The setup described—an item like a tongue depressor wrapped with a paper towel placed inside a dark, one-pint jar half-filled with water—is intended to attract gravid female mosquitoes to lay eggs on the towel substrate. The dark container and the moist environment mimic natural container habitats, signaling a suitable place for oviposition. After collection, the eggs on the towel can be counted or hatched in a lab to assess mosquito presence and abundance. This approach specifically targets eggs, distinguishing it from methods that collect larvae (larval sites), pupae (pupal devices), or adults resting in artificial sites.