Black soldier fly larvae can be used to feed other insects, as shown by the results of two recent studies. In one of them, larval meal was fed to lady beetles, which are beneficial biological control agents eating a wide variety of agricultural pests. In the second study, ground black soldier fly larvae were fed to mosquito larvae used for research. In both cases, black soldier flies provided suitable, but not optimal, diets. Still, this shows promise, especially if black soldier fly meal is mixed with other ingredients into formulated insect diets.

Riddick, E.W., Walker, R.C., Rojas, M.G. and Morales-Ramos, J.A., 2023. Evaluation of Black Soldier Fly Hermetia illucens as Food for Pink-Spotted Lady Beetle Coleomegilla maculata. Insects, 14(12), 902. https://doi.org/10.3390/insects14120902

The discovery of new and improved factitious and artificial diets is necessary for cost-effective rearing of predatory arthropods. This study evaluated Hermetia illucens black soldier fly (BSF) as a suitable alternative food source for rearing the predatory coccinellid Coleomegilla maculata (Cmac). The hypothesis that BSF larval powder was suitable food to support the growth, development, and reproduction of Cmac was tested in the laboratory. When compared to a standard in-house diet containing brine shrimp egg powder plus Chlorella vulgaris green algae and myristic acid (BSE+CM), the BSF and BSF+CM diets reduced immature growth and development. Immatures successfully reared to teneral adults were smaller when fed BSF or BSF+CM rather than BSE+CM. Combining BSF with a powdered artificial diet (AD), i.e., BSF+AD, did not improve predator growth or development, compared to Cmac reared on BSE+CM. Cmac oviposition responses, i.e., egg clutch production, to BSF vs. BSE+CM or BSF+AD vs. BSE+CM did not differ significantly. In conclusion, BSF has the potential to be food that supports Cmac oviposition behavior. Future research is necessary to discover an ideal mixture of BSF, BSE+CM, or AD that supports Cmac growth, development, and reproduction over multiple generations.

Ernawan, B., Sasmita, H.I., Fadilah, D.R., Fitriana, N., Sadar, M., Indarwatmi, M. and Nasution, I.A., 2023. Evaluation of black soldier fly Hermetia illucens (L.) larvae flour as larval diet for dengue vector mosquito Aedes aegypti (Diptera: Culicidae). Agriculture and Natural Resources, 57(5), 877-884.

Importance of the work: A low-cost ingredient for an Aedes aegypti larval diet is desirable for mosquito birth control programs.
Objectives: To investigate flour made from black soldier fly (BSF; Hermetia illucens) larvae as an alternative diet for Ae. aegypti larvae.
Materials & Methods: Prepupal BSF aged 18–21 d and two commercial animal diets were processed into flour and administrated to Ae. aegypti larvae. The nutrient contents were characterized and the experimental parameters were observed: L1 to pupation
developmental time, mortality, sex ratio, pupal weight and emergence rate.
Results: The BSF flour had the highest nutrient content compared to two commercial diets, based on proximate and amino acid analyses. Larvae reared on BSF flour were characterized by the slowest immature developmental time, lowest mortality and heaviest pupae compared to the other larval diets. In addition, larvae fed on BSF flour produced a significantly higher ratio of male-to-female pupae, while larvae fed on the other two diets were opposite owing to higher mortality of larvae.
Main finding: Although notably, the BSF larvae flour resulted in delayed immature growth, its nutrient content was sufficient for larval development. The use of BSF larvae flour as a larval diet may reduce the cost of male Ae. aegypti production in the sterile insect technique program