A recent study has revealed a new, simpler way of controlling mosquito-borne diseases. The study found that targeting only the very bottom of a room’s walls with insecticide can eliminate most mosquitoes, which can help to reduce the spread of diseases such as dengue, chikungunya, and Zika virus.
In some countries, indoor residual spraying is used to control mosquitoes that reside inside houses. However, this approach can be expensive because it requires coating a large surface area and, of course, is unhealthy to the human occupants.
To address the problem, researchers sought to identify the precise “kill zone” where most mosquitoes rest. The authors ran a series of experiments using sticky strips mounted at different wall heights to explore where mosquitoes choose to rest. Most mosquitoes chose to rest near the floor, with most of the insects choosing to perch on the first 20 centimeters of the wall, corresponding to 12.3% of the total wall surface.
The hotter the room, the further down the mosquitoes tended to rest, as the lower part of the room is typically cooler. By spraying insecticide in this bottommost zone, which could be colored black since mosquitoes seem to prefer dark surfaces, up to 85% of mosquitoes can be eliminated. This method is simple enough for individual householders to undertake using insecticidal or a handheld aerosol can, making it a more cost-effective and accessible way of controlling mosquitoes.