A checklist and commentary on the scarabaeid fauna of the Massachusetts offshore islands (Coleoptera: Scarabaeidae)

Records of seventy four species of scarab beetles are summarized from nine of Massachusetts’ offshore islands. The scarab fauna of these areas is characterized through a combination of recent collections from over 30 locations on eight of the islands, museum specimens and the literature. Though the bulk of recent collecting effort has been devoted to the islands of Martha’s Vineyard and Nantucket, scattered species records are also collated from Naushon, Nashawena, Pasque, Tuckernuck, Muskeget, Penikese, and Cuttyhunk Islands. With 56 documented species, Martha’s Vineyard, the largest of the islands, appears despite sampling bias to support the most diverse scarab fauna, followed by Nantucket, with 46 species. These two faunas account for 71 of the 74 species known from all the islands. A subset of these data consisting of scarabs from 2,700 pitfall trap samples is used to compare species richness and relative abundance at five sites on the two islands under var ying degrees of conser vation man- agement. Although recent conser vation has focused on grassland habitats, these represent a minority of the communities that occurred historically on these landscapes, and shrubbier habitats appear to support greater species richness than the less structurally complex grasslands.