Targeting male mosquito swarms to control malaria vector density

• Published in: PloS one 2017-03, Vol.12 (3), p.e0173273
• Main Authors: Sawadogo, Simon Peguedwinde, Niang, Abdoulaye, Bilgo, Etienne, Millogo, Azize, Maïga, Hamidou, Dabire, Roch K, Tripet, Frederic, Diabaté, Abdoulaye
• Format: Article
• Language: English
• Subjects: Aerosols; Age composition; Animal reproduction; Animals; Anopheles; Anopheles - drug effects; Anopheles gambiae; Aquatic insects; Biology; Biology and Life Sciences; Control; Control programs; Culicidae; Diptera; Feasibility studies; Female; Females; Housing; Humans; Insect Vectors - drug effects; Insecticide resistance; Insecticide Resistance - drug effects; Insecticides; Insecticides - administration & dosage; Insecticides - pharmacology; Malaria; Malaria - prevention & control; Malaria - transmission; Male; Males; Mating; Medicine and Health Sciences; Mosquito Control; Mosquitoes; Outdoor activities; Outdoors; Pesticide resistance; Physiological aspects; Physiology; Population; Population Density; Population number; Public health; Pyrethrins - pharmacology; Research and Analysis Methods; Residential areas; Science; Sleep; Spraying; Swarming; Swarms; Vector-borne diseases; Vectors
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0173273

Malaria control programs are being jeopardized by the spread of insecticide resistance in mosquito vector populations. It has been estimated that the spread of resistance could lead to an additional 120000 deaths per year, and interfere with the prospects for sustained control or the feasibility of achieving malaria elimination. Another complication for the development of resistance management strategies is that, in addition to insecticide resistance, mosquito behavior evolves in a manner that diminishes the impact of LLINs and IRS. Mosquitoes may circumvent LLIN and IRS control through preferential feeding and resting outside human houses and/or being active earlier in the evening before people go to sleep. Recent developments in our understanding of mosquito swarming suggest that new tools targeting mosquito swarms can be designed to cut down the high reproductive rate of malaria vectors. Targeting swarms of major malaria vectors may provide an effective control method to counteract behavioral resistance developed by mosquitoes. Here, we evaluated the impact of systematic spraying of swarms of Anopheles gambiae s.l. using a mixed carbamate and pyrethroid aerosol. The impact of this intervention on vector density, female insemination rates and the age structure of males was measured. We showed that the resulting mass killing of swarming males and some mate-seeking females resulted in a dramatic 80% decrease in population size compared to a control population. A significant decrease in female insemination rate and a significant shift in the age structure of the male population towards younger males incapable of mating were observed. This paradigm-shift study therefore demonstrates that targeting primarily males rather than females, can have a drastic impact on mosquito population.