Carabid beetle diversity and distribution in Boston Harbor Islands national park area (Coleoptera, Carabidae)

Abstract

As part of an All Taxa Biodiversity Inventory in Boston Harbor Islands national park area, an inventory of carabid beetles on 13 islands was conducted. Intensive sampling on ten of the islands, using an assortment of passive traps and limited hand collecting, resulted in the capture of 6,194 specimens, comprising 128 species. Among these species were seven new state records for Massachusetts (Acupalpus nanellus, Amara aulica, Amara bifrons, Apenes lucidulus, Bradycellus tantillus, Harpalus rubripes and Laemostenus terricola terricola—the last also a new country record; in passing we report also new state records for Harpalus rubripes from New York and Pennsylvania, Amara ovata from Pennsylvania, and the first mainland New York records for Asaphidion curtum). For most islands, there was a clear relationship between species richness and island area. Two islands, however, Calf and Grape, had far more species than their relatively small size would predict. Freshwater marshes on these islands, along with a suite of hygrophilous species, suggested that habitat diversity plays an important role in island species richness. Introduced species (18) comprised 14.0% of the total observed species richness, compared to 5.5% (17 out of 306 species) documented for Rhode Island. We surmise that the higher proportion of introduced species on the islands is, in part, due to a higher proportion of disturbed and open habitats as well as high rates of human traffic. We predict that more active sampling in specialized habitats would bring the total carabid fauna of the Boston Harbor Islands closer to that of Rhode Island or eastern Massachusetts in richness and composition; however, isolation, human disturbance and traffic, and limited habitat diversity all contribute to reducing the species pool on the islands relative to that on the mainland.

Laboulbeniales (Ascomycota) of the Boston Harbor Islands I: Species Parasitizing Coccinellidae and Staphylinidae, with Comments on Typification

“…The documented diversity of the BHI (Rykken and Farrell 2013) likely captures the true diversity of the islands. We expected lower diversity relative to the mainland, as is commonly found in island ecosystems (Gillespie and Roderick 2002) because of the islands' geographic isolation, small size, and level of human disturbance (Davidson et al 2011). Island areas and distances from the mainland are available at the National Park Service website (http://www.nps.gov/boha/).…”