David Owens, Extension Entomologist, owensd@udel.edu
Grapes
Continue scouting for potato leafhopper and Japanese beetle. Leafhoppers are susceptible to pyrethroids, while Japanese beetles are best controlled by Carbaryl (watch out for flaring mites, do not apply in very hot sunny conditions) followed by Imidan, Avaunt, Assail and Neem.
We captured our first grape berry moths of the season last week. Scouting recommendations from Cornell are to visually inspect 50 clusters in 4 locations in the vineyard and treat when injury approaches 6% of the clusters. Avaunt will also control grape berry moth caterpillars, along with pyrethroids which curiously are not labeled for Japanese beetles in grapes but are for other crops.
Small Fruit
Spotted wing drosophila catches continue to increase where we have traps. Expect numbers to continue rising as more and more wild hosts begin to produce (primary hosts right now are blackberries). Treatment options, depending on crop and preharvest interval, include Cormoran, Lannate, pyrethroids, Imidan, Verdepryn, Exirel, Malathion, Delegate and Entrust. Clean pick fruit often. Frequent fruit picking can help reduce the amount of time females have access to fruit. Remove and destroy fallen fruit or unmarketable fruit by placing in a clear plastic bag in the sun. Harvested fruit should be refrigerated promptly to stop larval development.