First Documented Wild Population of the “Hunter Fly”, Coenosia attenuata Stein (Diptera: Muscidae) in North America

SIMPLE SUMMARY: The hunter fly, Coenosia attenuata Stein (1903) (Diptera: Muscidae), is a species of biological control significance typically found in greenhouses. Phylogenetic data suggests Coenosia attenuata originated in the Mediterranean region. Here, we provide the first report of a wild hunter fly population in North America. In 2020 and 2021, Coenosia attenuata was captured in pan traps set in Georgia and South Carolina peach orchards. Specimens collected across multiple sites over two years were identified with morphological keys and confirmed via DNA barcoding, providing strong evidence for an established population in the Southeastern USA. ABSTRACT: Coenosia attenuata is a member of the tigrina-group of Coenosia (sensu Hennig 1964) and is a capable generalist predator in its larval and adult stages. C. attenuata is common in greenhouses worldwide, however, there are few documented cases of its presence in the wild. Here, we estimated C. attenuata presence in the southeastern USA peach orchards using pan traps. Over two years, a total of 717 specimens were collected from both commercially managed and fungicide-only managed peach orchards. C. attenuata is a known biological control agent in artificial greenhouse settings, but its impact on pest species in the wild is still unknown. For the first time in North America, we document an established wild population of C. attenuata, provide an overview of basic identification, and review potential benefits for biological control.