Figure 2.

(A). Schematic of the heat-seeking experimental setup. Mosquitoes were released into a meshed cage with two Peltier elements directly applied to one side: one maintained at ambient temperature (23 °C, outlined in blue), and one set up to warm up as described in (B). A camera recorded the landing activity on the Peltier elements. Through the top of the cage, a tube delivered a constant flow of humidified air to which pulses of CO₂ were added as described in (B). Schematic of ramping temperature steps of the “warm” Peltier element. The warm Peltier element was brought to ambient temperature (2 min) between each step (8 min), which increased the temperature by 5 degrees. Each step began with a 2-min pulse of CO₂ (in gray).