San Jose Scale
San Jose Scale crawlers are now active. We intercepted adult males between April 13 and April 20 from orchard sites in Dagsboro, Denton, and Port Penn. Effective insecticides include pyriproxyfen (Esteem), buprofezin (Centaur), neonics, organophosphates, and spirotetramat (Movento) and a premix Senstar. Of those, OP’s may have some codling moth efficacy and the OP’s and the neonic acetamiprid have some curative activity on plum curculio. Time your spray for 600–700-degree days (base 51 F) from about April 16 to hit peak crawler activity. If fruit damage was observed last year, this is the last time before winter dormancy that San Jose can be effectively managed.
Grapes
Potato leafhopper is active in some vineyards. Thresholds are near 1 leafhopper per leaf. Leafhopper nymphs are small and a yellowish white (early instars; similar in size to thrips) to a lime green (later instars) and tend to move sideways when disturbed. Check the underside of leaves. Control options include pyrethroids and neonicotinoids such as (but not limited to) acetamiprid.