Genomic insights into evolution and control of Wohlfahrtia magnifica, a widely distributed myiasis-causing fly of warm-blooded vertebrates

Wohlfahrtia magnifica is a pest fly species, invading livestock in many European, African and Asian countries, and causing heavy agroeconomic losses. In the life cycle of this obligatory parasite, adult flies infect the host by depositing the first-stage larvae into body cavities or open wounds. The feeding larvae cause severe (skin) tissue damage and potentially fatal infections if untreated. Despite serious health detriments and agroeconomic concerns, genomic resources for understanding the biology of W. magnifica have so far been lacking. Here, we present a complete genome assembly from a single adult female W. magnifica using a Low-DNA Input workflow for PacBio HiFi library preparation. The de novo assembled genome is 753.99 Mb in length, with a scaffold N50 of 5.00 Mb, consisting of 16,718 predicted protein-encoding genes. Comparative genomic analysis revealed that W. magnifica has the closest phylogenetic relationship to Sarcophaga bullata followed by Lucilia cuprina. Evolutionary analysis of gene families showed expansions of 173 gene families in W. magnifica that were enriched for gene ontology (GO) categories related to immunity, insecticide-resistance mechanisms, heat stress response and cuticle development. In addition, 45 positively selected genes displaying various functions were identified. This new genomic resource contributes to the evolutionary and comparative analysis of dipterous flies and an in-depth understanding of many aspects of W. magnifica biology. Furthermore, it will facilitate the development of novel tools for controlling W. magnifica infection in livestock.

Automated summary

In this study, a complete genome of W. magnifica was obtained and its evolutionary and comparative analysis was performed. The results revealed a close phylogenetic relationship between W. magnifica and Sarcophaga bullata, and expansions of gene families with various functions, including immunity, insecticide-resistance mechanisms, heat stress response, and cuticle development. This study provides important genomic resources for studying the evolution of dipterous flies and the biology of W. magnifica.