Distinct Swimming Behaviours in Pupae of Aedes, Anopheles and Culex Mosquitoes

Insect pupae are commonly considered an immobile, ecologically inactive life stage. Mosquito pupae, however, differ strongly from other holometabolous pupae in their mobility levels as they can actively move through their aquatic habitat. Despite this largely unique behavioural feature amongst insects, little is known about the pupal swimming behaviour and its associated costs and benefits in mosquitoes. As an improvement of our understanding of the ecology of mosquitoes, in particular of their juvenile stages, is required to develop or refine control strategies to prevent the transmission of deadly diseases, we here investigated the pupal surface swimming behaviour in 11 mosquito species of the genera Aedes, Anopheles and Culex. We observed distinct differences in their swimming behaviour, with Aedes pupae generally characterised by slow yet frequent movement bouts and high explorative behaviour, whereas Anopheles and especially Culex exhibit significantly fewer movement bouts but swim faster and cover larger distances per movement bout. These behavioural differences may reflect ecological adaptations tailored to the specific habitats of the tested species. In summary, our findings reveal a previously undescribed behavioural dissimilarity amongst species in this frequently overlooked mosquito juvenile life stage and highlight the importance of considering pupal behaviour when developing and improving mosquito disease control strategies.