Sea-Surface (Pleuston) Transport of Insects between Islands in the Galápagos Archipelago, Ecuador

Rafting of animals on floating debris is often proposed as a dispersal mechanism for the colonization of oceanic islands. Direct flotation of terrestrial arthropods on the sea surface itself, as pleuston, is less frequently suggested. Use of pleuston nets captured at least 68 species of insects and other terrestrial arthropods in 13 orders on the sea surface between islands in the Galapágos Archipelago, during the strong 1992 El Niñoclimatic event. The most abundant families were Aphididae, Cicadellidae and Miridae (Hemiptera), Tipulidae and Chironomidae (Diptera), and Formicidae (Hymenoptera). Strong El Niñoclimatic events probably create the most favorable conditions for seasurface transport of flightless arthropods to and between the Gálapagos Islands.