Pest Management Programs:
Because there are so many insecticide choices to use for control of CM and LR it is not enough to know how effective how each product is but there needs to be some concept of how to incorporate different products into a sound and rational pest management program. The remainder of our discussion will focus on strategies for using new insecticides to control CM and LR. Though control of other pests needs to be considered, this discussion should help to begin the process of incorporating new insecticides into your overall pest management program.
For this discussion, we will use a diagram of the CM life history showing time on both a temporal and degree-day scale with the generational duration of life stages shown as horizontal lines (Fig. 3). A “traditional” control program looks something like that shown in Fig. 3. It includes a prebloom oil plus Lorsban application that provides control of San Jose scale (SJS) and suppression of LR, European red mite (ERM) eggs and overwintering aphid eggs. Success applied at petal fall, near the beginning of the CM egg-laying period, provides additional control of LR; and four OP insecticide treatments, three Guthion applications and one Imidan are used to achieve CM control. This “traditional” CM/LR control program is a conceptual representation of the norm for the 1980s and early 1990s. In the 1980s Parathion was often used in place of Lorsban, and Bt products were used in place of Success, which had not yet been registered. The number of Guthion or Imidan applications was less than shown, averaging only about 2.5 per season. In the 1990s, Lorsban replaced Parathion in the prebloom program (Parathion registration was cancelled by regulatory action), and Success gradually replaced Bt products in the petal fall period. The number of Guthion or Imidan applications against CM averaged slightly over 3 per season by the mid-1990s.