SEA-SURFACE (PLEUSTON) TRANSPORT OF INSECTS BETWEEN ISLANDS IN THE GALAPAGOS ARCHIPELAGO, ECUADOR

Rafting of animals on floating debris is often proposed as a dispersal mechanism for the colonization of oceanic islands. Direct flotation o f terrestrial arthropods on the sea surface itself, as pleuston, is le ss frequently suggested. Use of pleuston nets captured at least 68 spe cies of insects and other terrestrial arthropods in 13 orders on the s ea surface between islands in the Galapagos Archipelago, during the st rong 1992 El Nino climatic event. The most abundant families were Aphi didae, Cicadellidae and Miridae (Hemiptera), Tipulidae and Chironomida e (Diptera), and Formicidae (Hymenoptera). Strong El Nino climatic eve nts probably create the most favorable conditions for sea-surface tran sport of flightless arthropods to and between the Galapagos Islands.