The phases and effects of low temperature exposure on embryonic development in Hermetia illucens (L.) (Diptera: Stratiomyidae)

Abstract
Research on the black soldier fly (Hermetia illucens (L.) Diptera: Stratiomyidae) is steadily increasing, with a focus on its larvae and applications thereof. The egg stage of this species has received less research. This study describes the phases of embryo development for BSF eggs and the potential of delaying embryo development by using a chilling protocol. The study found that when chilling eggs for 24 hours at 10 °C and 80% relative humidity, the development is paused for a full day. This study presents a window of opportunity for embryo ages, approximately 38-58 hours post oviposition, where the hatch success is the least affected (>80% hatching when compared to control). Outside of this window, the hatch success decreases to 70% and lower. The description of embryo development can be used as a reference tool for quality control purposes. The effect of treatments on eggs can be determined by identifying key processes in development. Furthermore, the chilling of embryos and thus pausing of development can be applied in a production setting.