Introduced Insect Fauna of an Oceanic Archipelago: The Galápagos Islands, Ecuador

Abstract

Oceanic islands are susceptible to invasion by exotic species of plants and animals that are introduced either intentionally or unintentionally by human action. Most tropical oceanic islands now have insect faunas that have changed markedly since their discovery by humans. The changes occurred with the introduction of foreign species by aboriginal peoples and later by colonization activities of Europeans (Carlquist 1965, 1974). For instance, the Hawaiian Islands now have more than 3,200 alien species of arthropods (Howarth 1990) and 2,621 species of introduced insects. Approximately 500 of these insects can be classed as pests (Beardsley 1991). More than 416 insect species were introduced intentionally (Nishida 1994), and it now is difficult to find indigenous insect species in most lowland areas of the Hawaiian islands. The faunal change in almost all tropical island insect faunas occurred before scientific inventories could document the processes and stages of change.