Since insect development depends on temperature, the insects are also developing very slowly. Figure 2 shows that the first flight of male scale in both 1998 and 1999 started much later and the total number of males was much smaller compared to 1997. May. In 1998, crawler emergence began during the first week of June. The crawler stage is most easily killed by Lorsban, Supracide, and Sevin. Peak crawler emergence can be observed using double-sticky tape wrapped around branches to catch crawlers as the crawl along the branch or by estimating when the peak of the male flight occurred and spraying 550 degree days later.
Oil smothers the insect and so is best applied when the scale have settled as whitecaps.
Since the majority of these insecticides do not control cottony cushion scale, their use results in a rapid increase in the numbers of this pest. One of the reasons is that the El Ni o conditions we had last year were perfect for soft scale growth and development. The orchards that are experiencing the worst problems are next to orchards that were sprayed with Esteem or Applaud. This is because the spray drift killed the vedalia beetle but not the cottony cushion scale. The vedalia beetle adults are not killed directly but their offspring do not complete development.