Revision of the Nearctic Species of the Genus 'Trixoscelis' Rondani (Diptera: Heleomyzidae: Trixoscelidinae). Smithsonian Contributions to Zoology Number 637.

摘要

Recent collecting in western North America has resulted in the discovery of many undescribed species of the genus Trixoscelis Rondani. These discoveries prompted this revision of all Nearctic species of the genus, especially since the last study of this fauna was published over 50 years ago (Melander, 1952) and is now woefully out of date and inadequate. For example, some of Melanders species are difficult to identify because many of the diagnostic characters have been found to be highly variable. Additionally, Melander focused very little on structures of the male terminalia, which we have found to be quite reliable for distinguishing species. In addition to describing the recently discovered Nearctic species, we are providing new data, synonymies, revised descriptions, comments, distributional data, and illustrations for all included species. A revised key to species is also provided. We have included a detailed treatment of T. costalis (Coquillett) from the Galapagos Islands in this study because this species had erroneously been reported from Arizona (Coquillett, 1902) and because we have had access to a series of 93 specimens from various Galapagos Islands.