Sterile codling moths,Laspeyresia pomonella(L.), released in a test orchard, were preyed on by yellow jackets,Vespulasp., at the release stations (White et al. 1969). In early summer 1970, yellow jackets were observed entering sex-attractant traps and removing live moths trapped by the sticky material (Stikem Special®); the yellow jackets were not trapped, because the material was usually not tenacious enough to hold them, though it did make rapid escape difficult and thus made it easier to catch the predator at work. Since this predation interfered with accurate counts of trap catches we needed a way to minimize it. The recently developed yellow jacket attractants and traps offered a particularly promising approach to the problem (Davis et al. 1969).