In recent years, insect larvae meals (LM) have become an intriguing ingredient for sustainable low-fishmeal/fish oil aquaculture feeds. There are reports of LMs being protective against disease in fish, and of insect-derived antimicrobial peptides (AMP) being protective against disease in chickens and pigs. This leads us to hypothesize that AMP in LM provide a protective effect against disease in fish. Because AMP expression in insects is known to increase many-fold during the innate immune response, we also hypothesize that any AMP-driven protective effect will be variable based on the degree of immune stimulation of the insect. To test these hypotheses, we will: 1) Define insect AMP expression and activity against common fish pathogens as a function of targeted changes in rearing conditions 2) Determine if LMs with elevated AMP content can provide increased protection against disease challenge This research will advance understanding of health and production in both aquaculture and entomoculture. Elucidating the basic biology of how insect larvae respond to different rearing conditions and, more significantly, the effect of that response on the properties of resultant LM, could provide a novel non-antibiotic approach to prevention of diseases in an aquaculture setting. In addition, this project will further serve the aims of this program by (i) contributing to the training of the next generation of agricultural researchers, and (ii) providing actionable information for current farmers.