Population Dynamics of Drosophila suzukii (Diptera: Drosophilidae) in Berry Crops in Southern Brazil.

Drosophila suzukii (Matsumura) is an invasive species originating in Southeast Asia and considered a severe pest in berry crops in several countries of the Northern Hemisphere and Europe. In South America, the species was first detected in 2013. The objective of the study was to monitor the seasonal activity of D. suzukii in commercial crops of blackberry, strawberry guava, surinam cherry, blueberry, and strawberry during two consecutive harvests and in three properties in the Southern region of Brazil during the 2015/2016 and 2016/2017 harvests, with the aid of traps baited with apple cider vinegar. The highest population peaks were observed during late spring to mid-fall in all areas and plant species studied. It was verified that temperature is the factor that most influenced the seasonal activity of D. suzukii in the field, promoting low catches of the species during winter. However, even during periods of low temperatures (winter period), the presence of D. suzukii in the crops was verified, demonstrating the species' ability to stay in place from year to year, surviving in alternative hosts such as Eriobotrya japonica, a common species in the region. The information on the time of the highest occurrence of the pest in different hosts presented in this study provides the basis for decision-making in relation to the management of D. suzukii, to avoid further economic damage.