Quality control methods for Aedes albopictus sterile male production

Abstract

The capacity of the released sterile males to survive, disperse, compete with wild males and inseminate wild females is an essential prerequisite to be evaluated in any area-wide integrated pest management (AW-IPM) programs including a sterile insect release method. Adequate quality control tests supported by standardized procedures need to be developed to measure these parameters and to identify and correct potential inappropriate rearing or handling methods affecting the overall male quality. In this study, we report results on the creation and validation of the first quality control devices designed to infer the survival and mating capacity of radio-sterilized Aedes albopictus males through the observation of their flight capacity under restricted conditions (flight organ device) and after stress treatment (aspirator device). Results obtained consistently indicate comparable flight capacity and quality parameters between untreated and 35 Gy irradiated males while a negative impact was observed with higher radiation doses at all observation time performed. The male flight capacity registered with the proposed quality control devices can be successfully employed, with different predictive capacities and response time, to infer the adult male quality. These simple and cost-effective tools provide a valuable method to detect and amend potentially sub-standard procedures in the sterile male production line and hence contribute to maintaining optimal quality and field performance of the mosquitoes being released.

Author summary

The absence of effective therapeutics and vaccines for emerging and re-emerging vector-borne diseases and the limited effectiveness of conventional vector control methods renovated the interest for the implementation and integration of the SIT and genetic control methods for successful area-wide integrated mosquito management strategies. These methods involve the release of mass reared insects genetically sterile, incompatible or resistant to pathogen amplification and transmission which need to effectively introduce in the wild target population adequate sterility or the desired genetically selected traits. The availability of easy and standardized quality control tests could facilitate the adoption of international procedures for mosquito strains evaluation and comparison and to assess strain suitability for effective mosquito genetic control applications.