Colonization of Pacific Islands by Black Flies (Diptera: Simuliidae)

Surveys of black flies on four Pacific islands revealed four species on Okinawa, two on Guam, and none on Rota or Saipan. Simulium aureohirtum Brunetti represents a new record for Guam and the only black fly that is not precinctive to Oceania. The banding patterns of the larval polytene chromosomes of this species are identical among populations from Guam, Okinawa, and Thailand, suggesting that the insular colonizations might be recent.