David Owens, Extension Entomologist, owensd@udel.edu
Stink Bug Numbers are High
High number of green stink bugs continue to be captured in our black light trap network, though not to the extent that they had been. Several sites are averaging between 30 and 40 per night. Continue scouting fruit crops for signs of damage. Green stink bugs are relatively susceptible to pyrethroids, whereas browns and brown marmorated are much less susceptible. For those two species, bifenthrin provides greater control than other pyrethroids.
Vineyards
Japanese beetles have begun emerging and they can defoliate grape vines if present in high numbers. They are most likely to be found on the edges of vineyards and in the upper canopy on wine grapes V. vinifera. Mature grape vines can tolerate a good deal of defoliation. Grapes are more sensitive to defoliation after veraison (onset of fruit ripening).
Blueberries and Blackberries
Spotted wing drosophila has been captured in traps around blueberry plantings. Blueberries are less susceptible to SWD damage, and the larvae tend to be less noticeable in blueberry plantings. As such, it some entomologists recommend monitoring fruit for signs of damage prior to treating. This also depends on your market. Cane berries on the other hand are much more attractive and much more susceptible to SWD damage. Treatments for SWD should begin when flies are captured near cane berries. Spray programs that start with the most effective, broad spectrum products have resulted in better control than those that begin with softer chemistry. You can find insecticide efficacy rankings here: https://swdmanagement.org/wp-content/uploads/2021/05/SWD-rankings-document-2021.pdf.