Chironomidae (Diptera) in Dominican amber as indicators for ecosystem stability in the Caribbean

A first overview on fossil chironomids in Dominican amber is given. This fossil assemblage seems to represent an insular fauna, very similar to its living relatives. Stenochironomus sp. and especially the true xylophagous, neotropical/southern North American Xestochironomus spp. prove the persistence of submerged dead wood in nutrient poor mountain streams in the Greater Antilles from the Miocene until today. Their abundance indicates that the special ecological conditions in extant Caribbean tropical mountain streams already ruled the ancient ecosystem. The results arising from the fossils of these freshwater organisms do not coincide with the faunal changes shown by other groups of insects. General systematic descriptions of new fossil representatives of Xestochironomus and Stenochironomus are given.