David Owens, Extension Entomologist, owensd@udel.edu
Tree Fruit
Brian Kunkel noted in the Ornamental Hotline that in northern Delaware, white peach scale crawlers should be active now. San Jose scale were captured in pheromone traps deployed between April 13 and April 20 from Frankford, Denton, and Port Penn. We are using April 16 as a biofix. Crawlers emerge around 400-450 degree days after biofix, this would probably occur at some point around or after May 20-25, and UC IPM recommends timing a treatment around 200 degree days after crawler emergence begins, probably around June 1. There is a good article on them here: https://hort.extension.wisc.edu/articles/san-jose-scale and here: https://ipm.ucanr.edu/agriculture/apple/san-jose-scale/. Esteem and Senstar contain pyriproxyfen a.i. and buprofezin is sold as Centaur. In addition, Diazinon and Ultor (spirotetramat) is labeled.