Infestation level of banana fruit fly (Bactrocera musae, Tryon) on Kalapua banana (Musa sp.) in Gazelle Peninsula, Papua New Guinea

Abstract

The banana fruit fly (Bactrocera musae Tryon), belonging to the family Tephritidae and subfamily Dacinae, is the main pest of bananas responsible for significant crop losses. In order to monitor the B. musae infestation, we collected banana fruit samples from four locations on the Gazelle Peninsula: Burit, Kereba, Vudal, and Vunapalading. On each field collection date, twelve banana bunches were chosen at random from the corresponding study sites. Following the removal of 100 individual fruits (fingers) from each fresh bunch at each study site, the fruits were weighed, thoroughly cleaned with rainwater three times, and then incubated in containers until the larval developmental stages were finished. When compared to the other three sites, the number of adults in the Kalapua bananas sampled from Burit was the highest. The banana fruits were divided into three main groups: “mature green”, “mature ripe”, and “immature green”. Mature green fruits produced a higher adult abundance than mature ripe fruits. Compared to the other two stages, immature green had the fewest adults. By fruit weight, Burit had the highest infestation (20.9%), while Vunapalading had the lowest (11.9%). After Kereba (14.7%), Vudal had the second-highest infestation (16.8%). Mature ripe fruit had the highest infestation (37.1%) by fruit weight, while immature green fruits had the lowest infestation (2.04%). A moderate level of infestation was observed in mature green fruits (17.1%). Regarding fruit count, the least infected fruits were immature green fruits (1.8%), moderately infected mature green fruits (17.0%), and highly infected mature ripe fruits (26.9%). Geographically, the Gazelle Peninsula has a Kalapua infestation level ranging from 11.9 to 20.9%, and a different maturity stage infestation level ranging from 2.04 to 26.9%. In general, the degree of infestation has escalated, and B. musae has established itself in the Gazelle Peninsula.