Effect of Cherry Cultivar and Trapping Height on Population Dynamics of Drosophila Fruit Flies in Cherry Orchards in Northern China

Abstract

In recent years, fruit flies (Drosophila spp.: Drosophilidae) have become an increasingly serious problem for cherry production in northern China. In this study, we examined the species composition and dynamics of fruit flies in cherry orchards using lure-baited traps placed at different heights, and in 3 different cherry cultivars, from Apr through Sep 2014 to 2016 in Qingdao, Shandong Province, China. The total number of fruit flies increased from yr to yr. Four species were captured: Drosophila melanogaster Meigen, Drosophila suzukii Matsumura, Drosophila hydei Sturtevant, and Drosophila immigrans Sturtevant (all Diptera: Drosophilidae). The dominant species was D. melanogaster, with 66.7% of the total captured, followed by D. suzukii (29.7%). Drosophila hydei and D. immigrans accounted for only 3.0 and 0.6%, respectively, and for these last 2 species, no peak period in abundance was observed. In general, Drosophila spp. appeared in Apr, and peaked around mid-Jul. Over the 3 yr span of the study, peak fruit fly abundance occurred later each yr, being at the end of Jun in 2014, and in the middle of Jul in 2015 and 2016. There were significant differences in the number of Drosophila species among cherry cultivars, as well as in the number of Drosophila trapped at different heights. The cultivar maturing in the middle of the season (cv. ‘Van') attracted the most fruit flies. The optimal height for trap placement was at 1 m above ground level, which is recommended as a standard height for Drosophila spp. population monitoring.