A mass rearing method to aliquot and hatch Aedes mosquito eggs using capsules

The sterile insect technique (SIT) is a sustainable genetic control method to effectively suppress mosquito vector populations below sanitary and nuisance thresholds. The SIT requires a cost-effective production and release of radio sterilized insects of high and consistent quality and quantity. In this study, we report a new procedure to hatch, aliquot and introduce Aedes albopictus and Aedes aegypti larvae into larval mass rearing units using dissolvable vegetable capsules containing brushed eggs and larval diet. The results demonstrated that the egg brushing procedures, the opening of the hatching container and the presence of diet in the hatching solution increased Aedes eggs hatching success. The diet added during the hatching process decreased the dissolved oxygen (DO) concentration, which constituted the main stimulus for egg hatching success in both species. However, a DO reduction below 3 mg/l can effectively stimulate hatching in both species regardless of the deoxygenation method adopted. The capsule method produced similar hatching success without affecting larval survival and pupation rates in comparison with standard hatching procedures. The use of capsules eliminates intermediate laborious procedures for hatching, counting and transferring larvae into mass rearing trays with an expected improvement in production times and costs for Aedes SIT operational programs.