Waterfowl-dung
Guides
Themira lohmanus
Lohman's ensign-fly
A relatively large and robust sepsid fly described in 2017 from two urban parks in New York City. Originally collected in 2007 and misidentified as Themira biloba, it was recognized as a distinct species through morphological differences (asymmetrical male surstyli), 4.46% COI DNA divergence, and complete post-zygotic reproductive isolation. The species is notable as the first new Themira species described from the Nearctic in 90 years despite occurring in one of the world's most intensively studied urban areas.