Chrysomelidae Of The Lesser Sunda Islands: Wallace's Line And The Crossing Of Worlds

Abstract

Th e Lesser Sunda Islands (LSI) is a chain of islands consisting of Lombok, Sumbawa, Sumba, Flores, and Timor. Based on published records combined with results from present survey, Chrysomelidae from LSI are represented by 144 species, including 59 new records and 63 endemics (44%). Th e new records represent an in- crease of 69% from the previous 85 recorded species. LSI has strong affi nity with the Oriental biogeographic Region with 41% of its fauna are derived from the Region. Although LSI is part of the Australasian biogeographic Region, the representation from Australia and New Guinea is very small, about 3%. Th e fi ve major subfamilies present in LSI are the Galerucinae (30%), followed by Alticinae (24%), Eumolpinae (15%), Cassidinae (15%) and Hispinae (6%). Species richness of the islands in LSI de- clines from west to east and further from the mainland (Sundaland). Th e same is true with the Oriental Region representatives; they decline in abundance from west to east further away from Wallace's Line, a biogeographic demarcation between the Oriental and Australasian Regions. But decline of the Oriental elements is compensated by an increase in species endemism. Th e Wallace's Line appears to be a faunal barrier, where a large number of genera and species, particularly from the Galerucinae are restricted to Sundaland, a subregion of the Oriental Region. Th e following six genera are not represented in Sundaland: Cleoporus and Dematochroma (Eumolpinae), Paropsis and Paropsisterna (Chrysomelinae), and Calomicrus and Paraplotes (Galerucinae).