Black soldier fly [BSF; Hermetia illucens L. (Diptera: Stratiomyidae)] larvae are very effective in transforming low‐grade food waste into valuable high‐end proteins and fat, in intensive production facilities. The production output of this species is growing quickly, but upscaling brings risks to the health status of the reared insects. Until now, not a single major case of disease outbreak caused by a pathogen in a BSF production unit has been reported. This contrasts with data on other species of mass‐produced insects, which have experienced various disease outbreaks, indicating that BSFs are comparatively resistant to insect diseases. Further, there are no records of natural infections caused by entomopathogens in BSF. In this review, the known entomopathogens of Diptera, especially BSF, and their potential risks for causing disease in these insects are summarized.

Rearing of the black soldier fly, Hermetia illucens, in mass production systems is increasing. Its use as both a bio-converter of organic waste and as feed for other livestock has transformed it into one of the most produced insects in the world. As a result, new research is needed to evaluate the risk of insect diseases affecting it and thus productivity. While some studies have focused on the larval stage of the flies, to date, few have assessed risks to the adult stage, vital to the production system. In this study, the susceptibility of adult black soldier flies to the entomopathogenic fungus, Beauveria bassiana KVL 03-122 was evaluated in laboratory experiments by quantifying mortality, egg-laying capacity, and sporulation when the flies were subjected to two concentrations of the fungus. The findings showed that adult flies are susceptible to the biocontrol agent B. bassiana, with high mortality and low egg count in the high dose treatment. Our results confirmed that adult black soldier flies appear susceptible to a fungal pathogen and we discussed the findings in relation to consequences for production.

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.