Codling moth larvae are the cause of the infamous “worm” in the apple or pear and is the immature stage of a small moth. This pest spends the winter as a mature larva in a pupal case on trunks of trees or in debris around the home orchard. When spring temperatures rise in March, the pupae mature and adult moths begin emerging in late March to April. Moths mate and lay eggs on leaves. Eggs hatch several weeks to a month later, and the larvae almost immediately bore into small fruit that has just begun to develop. To control codling moth with insecticide sprays, you have to apply the spray onto the larva just after it hatches and before it bores into fruit. Once inside the fruit, it is protected from any insecticidal treatments. This requires very careful timing. Sprays applied before the larvae hatch or after larvae bore into fruit won't be effective. Though not as accurate as timing using a more complicated day degree models and pheromone traps, you can time effective sprays by