Effect of three larval diets on larval development and male sexual performance of Anopheles gambiae s.s

Population replacement/elimination strategies based on mass-release of sterile or otherwise genetically modified (male) mosquitoes are being considered in order to expand the malaria vector control arsenal on the way to eradication. A challenge in this context, is to produce male mosquitoes that will be able to compete and mate with wild females more efficiently than their wild counterparts, i.e. high fitness males. This study explored the effect of three larval food diets developed by the International Atomic Energy Agency on the overall fitness and mating performance of male Anopheles gambiae s.s. mosquitoes (Kisumu strain). Larval development (pupation and emergence rate, development time) was monitored, and adult wing length and energy reserves at emergence (i.e. lipids, sugars, glycogen and proteins) were measured. Male sexual performance was assessed through an insemination test whereby one male and 10 virgin females were maintained together in the same cage in order to record the number of inseminated females per 24h. Our results show that males reared on Diets 2 and 3 performed best during larval development. Males provided with treatment 2.2 had a shorter development time and performed best in insemination tests. However, these males had the lowest overall lifespan, suggesting a trade-off between longevity and sexual performances which needs to be taken into consideration when planning release. The results from this work were discussed in the context of sterile insect techniques or genetic control methods which is today one of the strategy in the overall mosquito control and elimination efforts.