Effect of 2 sex-sorting time schedules on SIT facility management

Abstract

Improvements are needed in mosquito mass-rearing to effectively implement the sterile insect technique (SIT). However, managing this technique is challenging and resource intensive. SIT relies on mass rearing, sterilization, and release of adult males to reduce field populations. Maintaining an acceptable level of female presence, who can transmit viruses through biting, is crucial. Females are also essential for facility sustainability. Sex sorting plays a vital role in the production process, and our current mechanical sorting approach aims to obtain a high number of adult males with minimal female contamination within 24 h of pupation. Utilizing protandry helps control female contamination. While the 24-h sorting period achieves desired contamination levels, it may not yield enough females to sustain breeding lines, leading to increased labor costs that impact project sustainability. By delaying the sorting procedure to 48 h, we obtained sufficient females to sustain breeding lines, achieving a balance between male production and female contamination using the automatic version of the Fay–Morlan device as the sorting tool.

Upscaling the production of sterile male mosquitoes with an automated pupa sex sorter

“…The whole experiment was carried out three times. The male pupa recovery rate and female contamination rate were calculated as previously described (30). Specifically, the male pupa recovery rate was defined as the percentage of collected male pupae relative to the initial number of first-instar male larvae in the rearing tray, assuming an equal proportion of males and females.…”