Global population genetic structure and demographic trajectories of the black soldier fly, Hermetia illucens
Date
2021-05-05
Journal Title
Journal ISSN
Volume Title
Publisher
BMC
Abstract
Background: The black soldier fly (Hermetia illucens) is the most promising insect candidate for nutrient-recycling
through bioconversion of organic waste into biomass, thereby improving sustainability of protein supplies for
animal feed and facilitating transition to a circular economy. Contrary to conventional livestock, genetic resources of
farmed insects remain poorly characterised. We present the first comprehensive population genetic characterisation
of H. illucens. Based on 15 novel microsatellite markers, we genotyped and analysed 2862 individuals from 150 wild
and captive populations originating from 57 countries on seven subcontinents.
Results: We identified 16 well-distinguished genetic clusters indicating substantial global population structure. The
data revealed genetic hotspots in central South America and successive northwards range expansions within the
indigenous ranges of the Americas. Colonisations and naturalisations of largely unique genetic profiles occurred on
all non-native continents, either preceded by demographically independent founder events from various single
sources or involving admixture scenarios. A decisive primarily admixed Polynesian bridgehead population serially
colonised the entire Australasian region and its secondarily admixed descendants successively mediated invasions
into Africa and Europe. Conversely, captive populations from several continents traced back to a single North
American origin and exhibit considerably reduced genetic diversity, although some farmed strains carry distinct
genetic signatures. We highlight genetic footprints characteristic of progressing domestication due to increasing
socio-economic importance of H. illucens, and ongoing introgression between domesticated strains globally traded
for large-scale farming and wild populations in some regions.
Conclusions: We document the dynamic population genetic history of a cosmopolitan dipteran of South American
origin shaped by striking geographic patterns. These reflect both ancient dispersal routes, and stochastic and
heterogeneous anthropogenic introductions during the last century leading to pronounced diversification of
worldwide structure of H. illucens. Upon the recent advent of its agronomic commercialisation, however, current
human-mediated translocations of the black soldier fly largely involve genetically highly uniform domesticated
strains, which meanwhile threaten the genetic integrity of differentiated unique local resources through
introgression. Our in-depth reconstruction of the contemporary and historical demographic trajectories of H. illucens
emphasises benchmarking potential for applied future research on this emerging model of the prospering insectlivestock
sector.
Description
CITATION: Kaya, C., et al. 2021. Global population genetic structure and demographic trajectories of the black soldier fly, Hermetia illucens. BMC Biology, 19:94, doi:10.1186/s12915-021-01029-w.
The original publication is available at https://bmcbiol.biomedcentral.com
The original publication is available at https://bmcbiol.biomedcentral.com
Keywords
Black soldier fly (Hermetia illucens), Black soldier fly -- Population genetics, Black soldier fly -- Genetic diversity
Citation
Kaya, C., et al. 2021. Global population genetic structure and demographic trajectories of the black soldier fly, Hermetia illucens. BMC Biology, 19:94, doi:10.1186/s12915-021-01029-w