David Owens, Extension Entomologist, owensd@udel.edu
A photo of a young peach tree with San Jose Scale infested fruit came in last week. Fruit with scale on it will have red rings on the surface. The reddening is a reaction to scale saliva. Often when scale are present on fruit at harvest, it indicates a large population on the tree that, if not controlled, can result in significant tree health decline. A dormant oil spray is recommended between the last frost and bud break. If a dormant oil application is not performed, first generation crawlers can be targeted in the spring. Spray timing can be determined according to degree days after the first male is captured in a pheromone trap. Rutgers has had excellent efficacy from Centaur.