The female white peach scale, an armored scale, resembles a fried egg (Figure 1) because her yellow-orange body is covered with a white waxy secretion. Figure 2 shows a live “juicy” female with her cover removed; no eggs are present, yet.
Heavily infested twigs and branches seem covered with whitewash. As with all scales, these sap feeders can reduce growth of infested branches and delay bud break. Over time, infested branches may die. This scale can develop on several hundred host plant species, including stone fruits.
Moderate to heavy infestations will require a sustained management effort. In these cases, two dormant oil applications about 2 weeks apart should provide some pre-hatch reduction. Then, a well-timed application of a summer oil against first generation crawlers can give a high degree of control.
Monitor for first generation crawlers in early May by placing sticky tape near some live scales. Check the tape twice weekly for small, oval crawlers. This is the generation to target for a crawler spray because this egg hatch is relatively synchronized; eggs from later generations occur over a longer period of time. Second generation crawlers should be active about late July, and in southern Kentucky, a third generation may be active in early September.
By Lee Townsend, Extension Entomologist