The beetles of the Lesser Antilles (Insecta, Coleoptera): diversity and distributions.

Abstract

The island arc of the Lesser Antilles lies at the eastern margin of the Caribbean Sea in the Western Hemisphere, and stretches from the eastern end of the islands of the Greater Antilles (at the Virgin Islands), south to a position near the continental islands of Trinidad and Tobago at the north eastern corner of South America. The islands are a part of the West Indian Islands biodiversity “hotspot” and have been available for terrestrial colonization for about the past 15 million years. This is a status report on present knowledge of the beetle faunas of these islands, which is composed of 90 families, 1210 genera, and 2612 recognized species. Many additional species are not yet identified, or are unnamed, or remain to be discovered. Reported for the first time from the Lesser Antilles are four families, 49 genera, 105 species, and 1253 new island records. The largest families are Curculionidae (588 species), Staphylinidae (389 species), Chrysomelidae (181 species), Tenebrionidae (142 species), Cerambycidae (138 species), Scarabaeidae (127 species), and Carabidae (126 species). There are differing patterns of species distributions: 154 species are probably introduced by human activities; 985 are endemic species (limited to a single island); 465 are species endemic to more than one island of the Lesser Antilles; 212 are species limited to just islands of the West Indies; and 800 are native (naturally occurring) species which also have part of their distributional range in North, Central, or South America. Most of the widely distributed beetle fauna has probably come from South America by over-water dispersal. There is no compelling evidence for a vicariance origin of any part of the beetle fauna. Earlier colonists have had more time to form endemic genera (18) and endemic species. The more widely distributed species probably represent distributions achieved in and since the Pleistocene.