This study aimed to determine if ergot alkaloids (EA) would accumulate in yellow mealworm larvae (YML, Tenebrio molitor) when present in their diets and investigate effects on production and survival. Larvae were reared on one of four diets: a control, low, medium, and high containing 63, 3,863, 8,471 and 15,316 μg/kg total EA, respectively. Each diet had five replicates with 150 YML per replicate totalling 3,000 for the 21-day trial. Initial and final weights of the feed and larvae were collected. Ergot alkaloid concentrations in YML at d 21 were 32.6, 94.0 and 155.5 μg/kg in the low, medium, and high treatments respectively, with none detected in those fed the control diet. The frass from YML fed the control, low, medium and high diets contained 18, 364, 1,094, and 1,424 μg/kg total EA, respectively. Feed intake was reduced in larvae fed the low, medium and high treatments relative to the control at 23.3-24.9 g/21 d compared to 30.1 g in the control (P=0.02). Feed-to-gain ratios, average daily gain, and final body weights did not differ among treatments (P>0.05). The larvae did not display any preference for diets when allowed to choose between the four diets (P>0.05). Larvae accumulated only low levels of EA from their diets and although feed intake was depressed, growth was maintained. Further research is required to determine the safety of yellow mealworm reared on EA-contaminated diets.
