LLINs – Long-Lasting Insecticidal Nets

Long-Lasting Insecticidal Nets (LLINs) have a substantial effect on mosquitoes, even if the contact is brief, according to a fascinating new study of mosquito behaviour carried out at Liverpool School of Tropical Medicine.

The study set out to investigate how mosquitoes interact with bednets, now widely regarded as the most effective preventive element in malaria control.

Using infra red technology it tracked the flight of Anopheles Gambiae mosquitoes around bednets that were occupied by people. Four key behaviours were identified: swooping, visiting, bouncing and resting. Nearly 75% of the activity took place at the top of the bednet above the occupant’s torso.

Bednets that were treated with insecticides had a rapid effect on mosquitoes—contact of even less than a minute substantially reduced activity. After 30 minutes there was virtually no activity around the insecticide treated bednets. The researchers concluded that LLINs do not repel mosquitoes, but they function as a ‘highly efficient fast-acting baited insecticide trap.’

The paper ‘Infrared video tracking of Anopheles gambiae at insecticide-treated bed nets reveals rapid decisive impact after brief localised net contact’ is published in Scientific Reports. You can read it online here.

Parker, J.E.A. et al. Infrared video tracking of Anopheles gambiae at insecticide-treated bed nets reveals rapid decisive impact after brief localised net contact. Sci. Rep. 5, 13392; doi: 10.1038/srep13392 (2015)