Ultra-prolonged activation of CO2-sensing neurons disorients mosquitoes

Disrupting insect vector breath-seeking behaviour Female blood-feeding mosquitoes in search of a meal are attracted by carbon dioxide exhaled in the breath of their vertebrate hosts. The CO2 detection machinery is a tempting target in the search for ways of disrupting disease transmission by insect vectors. Anandasankar Ray and colleagues have now identified volatile odorants that modify the CO2 detection pathway in the three deadliest mosquito species (Anopheles gambiae, Aedes aegypti and Culex quinquefasciatus), and demonstrate the ability of odorants to disrupt CO2-mediated attraction behaviour. One compound has the novel property of causing ultra-prolonged activation of CO2-detecting nerve cells, with brief exposure resulting in prolonged disorientation. Others mimic or inhibit CO2-sensing. Compounds used in this proof-of-principle experiment, such as 2,3-butanedione, have properties that preclude use on humans, but this work could lead to the development of a new generation of insect repellents and lures that can work in small quantities.