Effects of Larval Density and Feeding Rates on the Bioconversion of Vegetable Waste Using Black Soldier Fly Larvae Hermetia illucens (L.), (Diptera: Stratiomyidae)

Abstract

The exploitation of fast degradation organic solid waste through the use of black soldier fly larvae Hermetia illucens constitutes a promising alternative in waste management given that it generates several products of added value (animal feed, larval compost, biofuels). The proper development of this process and its application at an industrial scale implies knowledge of the load capacity itself. In this context, with the present work the effects of larval density and feeding rate on the bioconversion of organic solid waste were evaluated. A composite central design was used to obtain response surfaces. The results show that both variables have a significant influence on the bioconversion process, with larval density the most influential element. Ideal conditions were determined, within the experiment’s range, to be a larval density of 1.2 larvae/cm2 and a feeding rate of 163 mg/larva/day (dry base) which produces up to 1.1 kg/m2/day of larval compost and 59 g/m2/day of larval biomass, on dry base. In order to generate the most quantity of biomass, the process tolerates larval density values of up to 5 larvae/cm2 without significant influence on the process as long as it is provided with a feeding rate no larger than 95 mg/larva/day (dry base).