The time to spray peach trees for worms depends on the worm species. While all peach trees can be sprayed during blooming, leaf rollers and peach twig borers require spraying while the tree is in its dormant stage. Mating disruptors used in the spring prevent Oriental fruit moth larvae infestations.
The first generation of leafrollers typically hatches in the spring, and a second generation hatches in the summer. Dormant sprays can prevent an infestation of the first generation, and a spray in the spring while the peach tree is in bloom combats the second generation. Peach tree borer larvae hatch in the spring, but they can be prevented when the peach tree is sprayed in its dormant season, with subsequent spraying while in bloom.
Oriental fruit moth larvae hatch after the moths lay eggs on the leaves of the peach tree. Mating disruptors prevent the moths from laying eggs, but they must be used along with a pesticide spray to be successful.