Seasonality of the Asian papaya fruit fly Bactrocera papayae Drew and Hancock (Diptera: Tephritidae) on guava Psidium guajava in peninsular Thailand

Abstract

The seasonality of Bactrocera papayae (Drew and Hancock), a notorious pests of fruits, was studied for one year (August 2011 to August 2012) in guava orchards and their surrounding environments in peninsular Thailand. The fruit fly was collected using Steiner traps baited with methyl eugenol as an attractant. Guava fruits were sampled and categorised into three developmental stages—ripe, mature and immature—with the aid of a fruit firmness tester. The fly species was trapped in the field throughout the season and was found exhibit distinct patterns of seasonal occurrence with two population peaks, during August-September and May. The density of B. papayae was high at all study sites. Fly population density was correlated with the interaction of temperature, rainfall and relative humidity. The fruit sampling revealed that the fruit fly emerged in larger numbers from ripe guava fruits.