Seasonal Population of Drosophila suzukii (Diptera: Drosophilidae) and Pesticide Use Pattern after Its Invasion in Caneberry Crops in Pennsylvania (USA)

Abstract

Drosophila suzukii (Diptera: Drosophilidae) is a major invasive pest of caneberries (e.g., blackberries and raspberries) and other thin-skinned fruit crops. In recent years, it has been reported as an economically important fruit pest in many countries. In caneberries, the timely detection and management of invasive insect pests such as D. suzukii is important to maintain profitability and avoid fruit export restriction. Invasions by such new pest species in commercial crop production often changes pesticide use patterns and frequency as growers try to control pest populations on their farms. In this study, we examined the seasonal population of D. suzukii and pesticide use patterns before and after D. suzukii invasion in primocane-fruiting raspberry and floricane-fruiting blackberry crop production in Pennsylvania. The results of seasonal monitoring conducted over two years showed higher populations of D. suzukii fruit flies during the settle period. The evaluation of crop-specific pesticide programs showed an increase in pesticide use frequency compared to the crop season before D. suzukii invasion in the blackberry planting. Similarly, over a five-fold increase in pesticide application was recorded in the raspberry planting in the year following invasion. The implications of increased pesticide use patterns in blackberry and raspberry production are discussed.