Patterns of Genetic Diversity and Mating Systems in a Mass-Reared Black Soldier Fly Colony

Abstract

The black soldier fly (BSF), Hermetia illucens, is a promising candidate for the emerging insect farming industry with favourable characteristics for both bioremediation and production of animal delivered nutritive and industrial compounds. The genetic management of commercial colonies will become increasingly important for the sustainability of the industry. However, r-selected life history traits of insects pose challenges to conventional animal husbandry and breeding approaches. In this study, the long-term genetic effects of mass-rearing were evaluated as well as mating systems in the species to establish factors that might influence genetic diversity, and by implication fitness and productivity in commercial colonies. Population genetic parameters, based on microsatellite markers, were estimated and compared amongst two temporal wild sampling populations and four generations (F28, F48, F52, and F62) of a mass-reared colony. Furthermore, genetic relationships amongst mate pairs were evaluated and parentage analysis was performed to determine the oc-currence of preferential mate choice and multiple paternity. The mass-reared colony showed a reduction in genetic diversity and evidence for inbreeding with significant successive generational genetic differentiation from the wild progenitor population. Population-level analysis also gave the first tentative evidence of positive assortative mating and genetic polyandry in BSF. The homoge-neity of the mass-reared colony seems to result from a dual action caused by small effective popu-lation size and increased homozygosity due to positive assortative mating. However, the high ge-netic diversity in the wild and a polyandrous mating system might suggest the possible restoration of diversity in mass-reared colonies through augmentation with the wild population.

Microsatellite-Based Genetic Structure and Hybrid Detection in Alpacas Bred in Poland

“…The allelic richness value of 2.885 was obtained for YWLL46, which indicated its poor utility. However, the values that we obtained, except for the YWLL46, were higher than those obtained by other authors for otters ( Lutra lutra ) [ 50 ], hares ( Lepus europaeus ) [ 51 ], arapaimas ( Arapaima gigas ) [ 52 ] and the black soldier fly ( Hermetia illucens ) [ 53 ], while they were lower than reported for dolphins ( Stenella coeruleoalba ) [ 54 ].…”

Gene expression differentials driven by mass rearing and artificial selection in black soldier fly colonies

“…Similar depression of gene expression variation has been noted over the domestication process for insect, bird and mammalian models (Liu et al, 2019). This decrease could be associated with the depletion of genetic diversity in captive populations over time, an observation made in prior assessments of BSF colonies undergoing mass‐rearing practices (Hoffmann et al, 2021; Rhode et al, 2020). Regarding the detection of DEGs, the use of two of the most widely cited programmes for differential expression analysis (Costa‐silva et al, 2017) was employed, namely DESeq2 and edgeR .…”

“…Despite this, little is known about the effects of domestication in BSF mass‐rearing environments. Previous work, in a commercialized rearing system, revealed rapid reductions in genetic diversity coupled with significant genetic and phenotypic divergence of captive BSF populations from wild progenitors and among successive generations (Hoffmann et al, 2021; Rhode et al, 2020). Although it is understood that many of these observations could be ascribed to founder effects, genetic drift, phenotypic plasticity and inbreeding, the underling roles of natural selection (for adaptation to a new environment) and artificial selection for desirable production traits on a functional genic level remains unquantified.…”

Development of semi-artificial feed in the larva stage of the black soldier fly Hermetia illucens (Diptera: Stratiomyidae)

“…The population in this study was the black soldier fly (BSF) insect (H. illucens), obtained from around community farms in the Surakarta area. First, wild parent BSF insects (F0) were caught using insect nets (Hoffman et al 2021). Then, BSF breeding would be carried out.…”