Why is dry ice used with light traps?

• A. It heats traps to attract mosquitoes.
• B. It repels non-target insects.
• C. It provides CO2 which attracts many mosquitoes, increasing numbers and diversity.
• D. It reduces trap effectiveness.

Answer: (C)

Dry ice works because it provides a steady source of CO2, which many host-seeking mosquitoes use as a cue to locate a nearby host. When dry ice sublimates, it releases CO2 gas that forms a plume near the trap, signaling mosquitoes to approach. This additional attractant increases both the number of mosquitoes caught and the diversity of species represented, making the trap more effective for surveillance. The other options don’t fit because dry ice does not heat traps, it does not act as a repellent, and it does not reduce trap effectiveness; it enhances attraction by supplying CO2.