Growers and consultants who use pheromone cards to track red scale are advised to have clean traps out at this time in order to correctly identify the start of the second flight. If temperatures remain warm for the next three weeks, the beginning of the second crawler emergence should occur the week of June 26. Populations of California red scale develop in response to temperature and various regions of the San Joaquin Valley accumulate temperature units at different rates. The insect is small, moving around and very susceptible to these insecticides. Esteem is very toxic to eggs and pupae of the vedalia beetle.
Vedalia beetle is the best natural control of the cottony cushion scale.
We need to avoid spraying Esteem during March through June in order to allow the vedalia beetle time to finish cleaning up the cottony cushion scale problems. Oil is still the recommended insecticide for the Aphytis release program. Generally it is applied during July. However, even oil has a negative impact on Aphytis because it can synchronize the scale stages and leave the Aphytis without 3 rd instar scale to lay their eggs in. Citricola scale is very sensitive to that broad spectrum insecticides, Lorsban, Supracide, and Sevin that we used for California red scale for many years.