Female black soldier flies apparently prefer laying their eggs next to mixed fruit rather than next to manure or a couple other substrates because fruit smells better. Cannot really blame them, even though it is not yet clear if feeding on fruit will be better for the larvae.

Zim, J., Chkih, H., Bouharroud, R., Sarehane, M. and Lhomme, P., 2023. Effect of various odour attractants on egg-laying activity of black soldier flies (Hermetia illucens). Journal of Insects as Food and Feed, ahead of print, https://doi.org/10.1163/23524588-20220139

The black soldier fly, Hermetia illucens (Diptera: Stratiomyidae), is a cosmopolitan fly. Its feeding behaviour, high productivity and the high value of its larvae in macronutrients (mainly lipids and proteins) makes this species one of the promising candidates for large scale insect farming and organic waste management. The reproductive rate, female oviposition preference and oviposition attractants of H. illucens are understudied. A better knowledge of the attractants involved in oviposition site choice would help maximising black soldier fly reproductive success. The current study aims to compare the efficacy of four food attractants on the oviposition activity of H. illucens females. The trial was conducted in a cage (11 × 1.25 × 0.9 m) with a volume of 12.38 m³ and containing 83,610 adults (6750 adults/m³). The cages were placed in a rearing room where the conditions were: T = 28 ± 1 °C, RH = 70 ± 5%, photoperiod of 16 h light: 8 h dark and light intensity = 8140 Lux). The tested feeds included a rabbit feed, fish waste (sardine, sardinella, and anchovy waste), a mixture of tropical fruits (pineapple, banana, papaya and mango), and fresh cattle manure. The performance of each feed attractant was evaluated in terms of the mass of eggs laid on the laying medium. This study showed that fruit mixture is the most efficient attractant, followed by fresh cattle manure and fish waste while the rabbit feed was the least efficient. The results of this study can be used to optimise the reproduction of the black soldier fly.