Evaluation of black soldier fly Hermetia illucens as food for the pink-spotted lady beetle Coleomegilla maculata

Authors: Riddick, Eric; Walker, Ryan; Rojas, Maria - Guadalupe; Morales Ramos, Juan

Submitted to: Insects
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/16/2023
Publication Date: 11/22/2023
Citation: Riddick, E.W., Walker, R.C., Rojas, M.G., Morales Ramos, J.A. 2023. Evaluation of black soldier fly Hermetia illucens as food for the pink-spotted lady beetle Coleomegilla maculata. Insects. 14(12):902. https://doi.org/10.3390/insects14120902.
DOI: https://doi.org/10.3390/insects14120902

Interpretive Summary: Discovery of new and improved diets are necessary to mass rear predators of high quality to support biological control of plant pests on crop plants. This study evaluated black soldier fly (BSFly) as an alternative food source for mass rearing the pink spotted lady beetle, which is a predator of aphids. The hypothesis that BSFly larval powder supported growth, development, and reproduction of the predator was tested in the laboratory. When compared to a standard in house diet containing brine shrimp egg powder plus algae and a myristic acid (BSE+CM), the BSFly diet reduced immature growth and development. Immatures successfully reared to adults were smaller when reared on BSFly. In a separate experiment, combining BSFly with an artificial diet (AD) in a 50: 50% ratio (i.e., BSFly+AD) did not improve predator growth or development. Predator oviposition responses to BSFly versus BSE+CM or BSFly+AD versus BSE+CM did not differ significantly. However, predator females tended to require more days to initiate oviposition when reared on BSFly. In conclusion, BSFly has potential as food for rearing predator adults but not larvae.

Technical Abstract: Discovery of new and improved factitious and artificial diets are necessary for cost effective rearing of predatory arthropods of high quality to support augmentative biological control of plant pests. This study evaluated Hermetia illucens black soldier fly (BSFly) as a suitable alternative food source for rearing the predatory coccinellid Coleomegilla maculata (Cmac). The hypothesis that BSFly larval powder was suitable food to support 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 green algae and myristic acid (BSE+CM), the BSFly diet reduced immature growth and development. Immatures successfully reared to teneral adults were smaller when fed BSFly rather than BSE+CM. In another experiment, combining BSFly with a powdered artificial diet, AD, i.e., BSFly+AD, did not improve predator growth or development, in comparison to Cmac reared on BSE+CM. Cmac oviposition responses, i.e., egg clutch production, to BSFly vs BSE+CM or BSFly+AD vs BSE+CM did not differ significantly. In conclusion, BSFly has potential as food for rearing Cmac adults, but not larvae. Future research could evaluate the addition of plant derived natural compounds to BSFly powder to boost oviposition rates.