Evaluation of the efficacy of novel, meat-free and easily sterilisable artificial diet for mass rearing of Lucilia sericata (Diptera: Calliphoridae) larvae for medical applications

Medically significant Lucilia sericata larvae lack a standardised, reproducible, animal tissue-free, and sterilisable diet for rearing. In this study, we developed and evaluated a diet made from dried milk, protein powder, cholesterol, amino acids, and vitamins with a defined macronutrient composition. We demonstrated that this formulation supports larval development comparable to that of control liver diet. This diet composition was also tested with a deficiency in each ingredient to determine their role and influence on larval development. Specifically, the effects of these diets on the following traits of the fly were measured: third instar larvae length and weight, pupal weight, pupation percentage, eclosion percentage, adult longevity, and egg-laying capacity across two generations. Based on performed studies, we demonstrated that Lucilia sericata did not successfully develop on a diet lacking vitamins. Moreover, reduced third instar larval survivorship was observed in diets deficient in protein and cholesterol, whereas higher eclosion failure occurred in diets lacking milk, protein, and Ω-acids. These results indicate that each ingredient is important in the larval development. Overall, larvae reared on liver-based diets showed similar characteristics to those reared on artificial diets. Furthermore, subsequent generations of Lucilia sericata reared on this diet exhibited normal development and reproductive capacity, and their eggs produced viable offspring. This represents a potentially novel formulation, with sterilisable and readily available ingredients, and a meat-free composition that can be easily produced and used for medical applications.