Video monitoring has shown that mosquitoes spend most of the time near the head of a person lying under a bednet at night.

Credit: J. R. Soc. Interface/CC by 4.0

Mosquitoes carry several human diseases but are difficult to study in the field. David Towers at the University of Warwick in Coventry, UK, and his co-workers used infrared light-emitting diode backlighting to make mosquitoes visible on video. They filmed the insects with two cameras at night around a mosquito net in the laboratory and in the field in Tanzania. The team developed algorithms to track individual mosquitoes, and found that the insects focused their efforts around the roof of the net, above the person's head (mosquito tracks pictured as coloured lines). The mosquito species that transmits West Nile virus (Culex quinquefasciatus) tended to be more active than the carrier of human malaria, Anopheles gambiae.

The technique could help to improve understanding of how mosquito behaviour affects disease transmission.

J. R. Soc. Interface 13, 20150974 (2016)