Disrupting insect vector breath-seeking behaviour

Credit: Stephanie Turner

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. Cover background: A. Bradshaw/Getty.