David Owens, Extension Entomologist, owensd@udel.edu
Grapes
Japanese beetles have begun emerging this week. Scout vineyard edges for beetle congregations. Wisconsin entomologists recommend using a 30% defoliation threshold before using an insecticide but note that other fruit crops may be more sensitive to defoliation. Effective materials include carbaryl, indoxacarb, acetamiprid, and azadirachtin.