Flower thrips (Thysanoptera: Thripidae) dispersal from alternate hosts into southern highbush blueberry (Ericales: Ericaceae) plantings

Abstract

Frankliniella bispinosa (Morgan) is the key pest of southern highbush blueberries (Vaccinium corymbosum L. × V. darrowi Camp) in Florida. Thrips feeding and oviposition injury to developing flowers can result in fruit scarring that renders the fruit unmarketable. Previous studies have shown that flower thrips can disperse into cultivated crops from surrounding host plants. Therefore, the objectives of this study were to identify alternate hosts of F. bispinosa adjacent to blueberry plantings and to determine if F. bispinosa emigrates into blueberry plantings from these hosts. Plant surveys conducted in Apr of 2007 and from Nov 2007 until Mar 2008 revealed several reproductive hosts of F. bispinosa, including: Carolina geranium (Geranium carolinianum L.), white clover (Trifolium repens L.), and wild radish (Raphanus raphanistum L.). In a subsequent study, we monitored thrips population development in a blueberry planting and in an adjacent white clover field during early spring in 2009 and 2010. Flower thrips populations in the white clover and blueberry planting developed at the same time with the highest numbers of thrips recorded from the center of the blueberry field in both years. Although white clover grows abundantly adjacent to blueberry plantings in the spring our findings indicate that clover does not appear to be a significant source for thrips inoculation of southern highbush blueberry plantings in Northern Florida.