Codling moth larvae are the guys you might occasionally meet when you bite into an apple. They can also damage pears, walnuts and quince. These simple sticky traps are designed to hang in your fruit trees at the end of the bloom period to catch the male moths which have been attracted by the non toxic pheromone lure. For adequate coverage 1 or 2 traps per mature tree are suggested. Some larger orchards use several traps as a monitor to tell them when they need to intervene with insecticide products such as BTK.