Control of codling moth in small plots by mating disruption: alone and with limited insecticide

Mating disruption alone and mating disruption supplemented with limited applications of either azinphos-methyl or fenoxycarb was evaluated in 0.11-0.30 ha plots for the control of codling moth Cydia pomonella (L.) (Tortricidae: Olethreutinae) populations. Where populations were low mating disruption alone was sufficient to keep codling moth damage levels below 1% at harvest. 'Low' was defined as no more than 0.2% damage at harvest and fewer than 1.3 larvae/metre of trap band from January-March inclusive in the previous season. Neither mating disruption alone nor when supplemented with azinphos-methyl or fenoxycarb during the first spring generation gave commercially acceptable levels of control in other than low density populations. Small plot size may have contributed to the failures. At the high density site unintentional supplementary control provided by drift of azinphos-methyl from border areas to which it was applied throughout the season gave excellent control in the first year and suggested an interaction between low dosages of insecticide and pheromone treatments that enhanced the disruptive effect of the latter.