To escape after taking a blood meal, a mosquito must exert forces sufficiently high to take off when carrying a load roughly equal to its body weight, while simultaneously avoiding detection by minimizing tactile signals exerted on the host's skin. We studied this trade-off between escape speed and stealth in malaria mosquitoes, Anopheles coluzzii, using 3D motion analysis of high-speed stereoscopic videos of mosquito take-offs and aerodynamic modelling. We found that during the push-off phase, mosquitoes enhanced take-off speed by using aerodynamic forces generated by the beating wings in addition to leg-based push-off forces, whereby wing forces contributed 61% to the total push-off force. Exchanging leg-derived push-off forces for wing-derived aerodynamic forces allows the animal to reduce peak force production on the host's skin. By slowly extending their long legs throughout the push-off, mosquitoes spread push-off forces over a longer time window than insects with short legs, thereby further reducing peak leg forces. Using this specialized take-off behavior, mosquitoes are capable of reaching take-off speeds comparable to those of similarly-sized fruit flies, but with weight-normalized peak leg forces that were only 27% of those of the fruit flies. By limiting peak leg forces, mosquitoes possibly reduce the chance of being detected by the host. The resulting combination of high take-off speed and low tactile signals on the host might help increase the mosquito's success to escape from blood-hosts, which consequently also increases the chance that they transmit vector-borne diseases, such as malaria, to future hosts.
|Date made available||17 Aug 2017|
|Publisher||Wageningen University & Research|
Muijres, F. T. (Creator), Chang, S. W. (Creator), van Veen, W. G. (Creator), Spitzen, J. (Creator), Biemans, B. (Creator), Koehl, M. A. R. (Creator), Dudley, R. (Creator) (17 Aug 2017). Data from: Escaping blood-fed malaria mosquitoes minimize tactile detection without compromising on take-off speed. Wageningen University & Research. 10.5061/dryad.1b312