Feeding in the adult of Hermetia illucens (Diptera Stratiomyidae): reality or fiction?

Abstract

Hermetia illucens (L.) (Diptera Stratiomyidae) is a promising species as alternative protein source for animal feed, able to convert a wide range of organic materials. The knowledge on larval biology, development, nutritional needs, and nutritional composition is rich, while few information is available on adult traits. The aim of the present study was to investigate the influence of the adult nutrition on the survival, the longevity and the ovaries development of H. illucens. In detail, three food sources have been compared to starvation. Water, a sucrose solution and a protein solution were given to new emerged adults and data on longevity and ovary development were acquired. Trials were conducted on single specimen and on a cohort of adults. In all the trials, starved adults survived significantly shorter than all other thesis. When adults were maintained isolated, the survival was significantly influenced by the nourishment: longevity was longer when adults were fed with a sucrose solution, while the supply of a protein source provided a lifespan significantly higher than starvation but similar to water or to sucrose solution. In cages longevity was always shorter than in isolated adults for both males and females and the overall trend was similar to single individual trials with the exception of protein solution. Ovary development of females under different nourishment did not show differences. More studies are necessary to identify a correct nutrition considering the integration of different chemical compounds to obtain optimal adult performance in terms of longevity and reproduction.

Nutrient Recapture from Insect Farm Waste: Bioconversion with Hermetia illucens (L.) (Diptera: Stratiomyidae)

“…We assessed how different rearing substrates influenced the larval growth in terms of final larval weight reached and development time, and the efficacy in waste reduction and bioconversion. As already observed, growth parameters for both larvae and adults were greatly influenced by the composition of feed substrates [22,25,41,49,50]. All experimental substrates allowed larval growth and emergence of H. illucens adults.…”

“…Adult dimension (weight and length) strongly reflected the trend of the weight of the preimaginal instars. In fact, it is known that H. illucens accumulates its fat body only during the larval stage, while adult nourishment is less important and mostly influences longevity [41,51,56]. As is typical in Diptera, adult females always weighed more than males [57,58].…”

Optimization of Hermetia illucens (L.) egg laying under different nutrition and light conditions

“…Nowadays research is focused on facing the challenges raised by indoor mass rearing of these insects. Although abundant studies were performed on the optimization of larvae rearing [3,[14][15][16][17], additional information on the adult breeding strategies must be deepened. Expanded knowledge on the individual reproductive potential of females, adult density and nutrition requirements [18,19], may increase egg production and achieve a successful industrial process.…”

“…The fecundity of females may be influenced by the nutritional content available during larval stages [3,28] or by the type of nutrition administrated during adult stage [17,18]. Moreover, a diet rich in proteins could increase the oviposition performances of BSF females [18].…”

“…Egg hatchability seemed to be positively influenced by LED lighting compared to fluorescent tubes [15] while a positive influence was observed by feeding adults with a combination of sugar, milk powder and bacteriological peptone, although the difference was not significant if compared to agar, water or no nutrition [18]. Although a comparison between adult life span under different light influence would be more complicated, due to different experimental conditions, focusing on nutrition has shown that the addition of sugar in adult diets increases longevity up to 3 times in males and 2 times in females [17,27]. Based on the availability of nutrients in the natural habitat, studies suggested that diets rich in proteins or sugar improve the longevity of BSF adults [17,18].…”