Larvae occasionally enter the apple calyx and feed unnoticed within the seed cavity. Most injury to apples is caused by second brood feeding, although in some years first brood injury can exceed that caused by the following generation. Injury to fruits destined for fresh markets has a greater economic impact since their cash value is much higher compared to that of processing grade apples. Generally, TABM injury does not reduce the grade of processing apples, but it can affect the rate of fruit drop and storageability of those apples by promoting decay, both of which can have an economic impact on the grower and processor. In order to time insecticide applications more efficiently when eggs hatch, begin monitoring and recording daily maximum and minimum temperatures from the first sustained trap catch.
Careful observation is required to detect egg masses.
Mark locations of egg masses with flagging ribbon so that development can be followed. If the percentage of first brood injured apples does not equal one of the values in Table 1, it can be inserted into the equation at the bottom of Table 1 and the predicted amount of second brood injury can be calculated. Predicted TABM brood II fruit injury estimated from the percentage of brood I injury. A second application should be made 300 DD after the first application. These recommendations are based on applying complete sprays.