Abundance and Seasonal Occurrence of Pest Fruit Flies (Diptera: Tephritidae) in Residential and Rural Areas of Oahu (Hawaiian Islands)

Abstract

A trapping network is maintained on Oahu (Hawaiian Islands) for early detection of invading fruit flies. The 359 sites are concentrated around the main ports of entry in the south, the community gardens throughout the island, and the commercial farming areas in Waialua and northeast Oahu. Data on abun- dance and seasonal fluctuation cycles, based on five years (2009-2013) of male lure and protein trapping data, are presented for three species of pest fruit flies, Bactrocera cucurbitae (Coquillett), B. dorsalis (Hendel) and Ceratitis capitata (Wiedemann). Over 87,000 samples yielded 8.5 million flies of the four established species (54.9% B. dorsalis, 43.7% B. cucurbitae, 1.4% C. capitata, plus a few B. latifrons (Hendel)). No new invading species were collected. 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 for B. dorsalis or coffee for C. capitata. The high correlation between captures of males in male lure traps and females in protein traps for the three species suggests that both attractants can be used to monitor seasonal abundance.