Hypsithermal-relict
Guides
Ospriocerus
robber flies
Ospriocerus is a genus of robber flies (family Asilidae) containing approximately 17 described species. These large, predatory flies are primarily associated with grassland and prairie habitats across western North America. Several species exhibit mimetic coloration resembling spider wasps (Pompilidae), with black bodies and red or orange abdominal markings. The genus has been documented as far north as Canada and south into Mexico. Species such as O. abdominalis represent significant range extensions when found in eastern localities, highlighting the importance of remnant prairie conservation.
Ospriocerus aeacidinus
robber fly
Ospriocerus aeacidinus is a large robber fly (family Asilidae) native to western North America. The species was historically recorded as far east as Nebraska, Kansas, Oklahoma, and Texas, but has been documented in recent years in relictual hilltop prairie habitats in northwestern Missouri and southwestern Illinois—representing significant eastern range extensions. Adults are active predators with wasp-mimetic coloration. The species is considered a grassland specialist associated with dry prairie remnants, particularly those linked to the Loess Hills landform.