Diet particle size influences tropical house cricket life history

Artificial diets are costly to produce, so diet efficiency is critically important to the success of mass rearing insects. One way to improve feed efficiency is through dietary particle size optimization. We tested whether individual crickets (Gryllodes sigillatus) reared on diets of different particle sizes (0.088-0.125 mm, 0.5-0.7 mm, and 1.0-1.4 mm) would grow differently. Crickets fed a diet ≥0.5 mm grew heavier during the first three weeks but weighed the same after six weeks regardless of diet size. We also tested for dietary size preference, and given a choice crickets consumed the most feed from the 1.0-1.4 mm diet. Next, we tested whether grinding diet to a powder and also pelleting the powder could influence life history. Powdered diet did not influence growth or development, but crickets fed a 2 mm pelleted diet grew larger body size. Overall, our results demonstrate that diet particle size can be leveraged to enhance cricket life history traits important to mass production, as growth was accelerated on larger particle size diets and crickets preferred to eat larger-sized diets. Researchers focusing on physical properties of insect diets should carefully consider the timing of growth and development milestones through which diet particle size may influence feed efficiency.