Abundance and seasonal occurrence of pest fruit flies (Diptera: Tephritidae) in residential and rural areas of Oahu (Hawaiian Islands)

A trapping network (359 sites), with male lure and protein traps, is maintained on Oahu (Hawaiian Islands) for early detection of invading fruit flies, around the main ports of entry in the south, the community gardens throughout the island, and the commercial farming areas in Waialua and northwest Oahu. Data on abundance and seasonal fluctuation cycles are presented for three species of pest fruit flies, Bactrocera cucurbitae (Coquillett), B. dorsalis (Hendel) and Ceratitis capitata (Wiedemann), based on five years of trapping (2009-2013). Over 87,000 samples yielded 8.5 million flies of the established species (54.9% B. dorsalis, 43.7% B. cucurbitae, 1.4% C. capitata, plus a few B. latifrons (Hendel)), but no new invaders. Trap captures for all three species were highest during summer months each year, with secondary peaks for B. cucurbitae later in the year in rural areas of southern Oahu, related to cucurbit host commercial production. At one site, with coffee in cultivation, C. capitata peaked between October and December. Seasonal cycles of B. dorsalis and C. capitata in residential areas appeared to be determined by the fruiting of ornamental trees and shrubs, including mango, rather than guava and coffee. The high correlation between captures of males in male lure traps and females in protein traps for the three species suggests that both attractants are good tools to monitor seasonal abundance.