Growth performance of the black soldier fly, Hermetia illucens larvae (Linnaeus, 1758) fed on honeybee propolis-treated wheat bran

Abstract

Insect-based meals such as the black soldier fly Hermetia illucens (Linnaeus, 1758) larvae (BSFL) meal have shown promising results as aqua feed protein supplements. BSFL voraciously consume organic waste converting the nutrients into larval biomass containing 37-63% protein. However, to enable large-scale production of BSFL, the growth performance of BSFL needs to be enhanced. Natural additives such as propolis (a honeybee product) have shown potential to enhance the performance of farmed animals. This study examined the growth performance of BSFL fed on wheat bran treated with ethanol extracted honeybee propolis. A 45-days experiment was carried out in which triplicate groups of 100 BSFL (5 days-old) were each fed on 0.5 kg of wheat bran with a 70% moisture content and treated with either 0, 0.2, 0.4, 0.6 or 0.8 g of ethanol extracted propolis. The mean weight of BSFL at pre-pupae stage, rate of pupation and emergence of adult flies were assessed. The findings indicate that at the end of the first five days, the mean weight of larvae reared on propolis-treated substrate was significantly higher than the weight of larvae on propolis-untreated substrate. The highest mean weight of BSFL was recorded with 0.6 g propolis-treated wheat bran. The highest cumulative mean number of pupae was recorded in wheat bran treated with 0.8 g of propolis. Further, the highest cumulative mean number of adult flies were recorded in wheat bran treated with 0.8 g of propolis. All pupae from propolis treated substrate emerged into adult flies earlier (5 days) compared to other treatments. Therefore, propolis addition to wheat bran enhanced the growth performance of BSFL. However, more studies are necessary to determine the effect of propolis on reproductive performance of BSF and the proximate composition of BSFL.