David Owens, Extension Entomologist, owensd@udel.edu
Strawberry
Continue scouting for spider mites and tarnished plant bug in strawberry. Beat 30 flower trusses on plastic to dislodge nymphs. Nymphs look similar to aphids, but will move quickly off the plastic. UMass has a good table explaining sequential sampling where, depending on the number of insects and flower clusters examined, control is either not necessary – stop sampling, necessary – stop sampling, or if in between – keep sampling. This can result in a significant time savings. (https://ag.umass.edu/fruit/fact-sheets/strawberry-ipm-tarnished-plant-bug).
You can also use a beat sheet for sampling, black sheets are better for finding nymphs. If beating whole plants, the threshold is 1 bug per 20 plants. There is a plethora of available synthetic insecticide treatments available. Several pyrethroids are labeled, with varying pre harvest intervals. Malathion is also labeled, as is Assail. Newer chemistries include Apta (also has some powdery mildew activity), Transform, and Beleaf. Among these, only Beleaf is rated as having low bee toxicity. Be careful not to spray when bees are active; you do not want to risk having deformed fruit by poor pollination when trying to prevent deformed fruit by TPB. PyGanic and azadirachtin are organic options.
Tree Fruit
Continue scouting for plum curculio. Beat branches or look at fruit for signs of adult feeding (round holes) or oviposition (crescent shaped holes).