In the last two decades, three previously common coccinellids (Adalia bipunctata (L.), Coccinella transversoguttata richardsoni Brown, and Coccinella novemnotata Herbst) have declined in abundance in South Dakota, while two invasive species (Coccinella septempunctata (L.) and Harmonia axyridis (Pallas)) have become established there. The objectives of this study were to survey coccinellids in various habitats in South Dakota to better characterize the current coccinellid fauna, determine the extent of exploitation by invasive coccinellids, and possibly identify refuge habitats of previously common coccinellid species. Overall, 2827 coccinellids, comprising 23 species, were collected on yellow sticky traps in field and woody habitats and during timed visual searches in field crops. Adalia bipunctata was found during additional sampling in Butte County in western South Dakota. However, it was not present in samples from eastern and central parts of the state, which is consistent with previous findings that this species is absent from those areas. Coccinella transversoguttata richardsoni and C. novemnotata were absent at all sites sampled. Scymnus kansanus Casey was collected for the first time in South Dakota among arboreal habitats. Harmonia axyridis (Pallas) expanded its geographic range into central South Dakota by 2002 and western South Dakota by 2004. Invasiveness of H. axyridis and C. septempunctata was evident by their presence in a wide variety of habitats surveyed, dominance of larval coccinellid assemblages, and predation upon non-target species of aphids. Harmonia axyridis was the most abundant larval coccinellid in maize and C. septempunctata was the most abundant larval coccinellid in intercropped wheat-alfalfa. Harmonia axyridis preyed upon Stegophylla quercicola (Monell), Aphis nerii Boyer de Fonscolombe, and Aphis asclepiadis Fitch in the field. Both H. axyridis and C. septempunctata preyed upon Hyalopterus pruni (Geoffroy) in the field.