Large-Scale Test of Orchard Sanitation to Control Codling Moth: Progress Report

Control of codling moth in organically‐managed apple orchards by combining pheromone‐mediated mating disruption, post‐harvest fruit removal and tree banding

“…Recent failure of mating disruption in organic apple orchards of Ontario (Trimble, 1995), where damage levels after one year were estimated at 1.1-3.3%, and increased 4-5 fold during 3 years of suc-cessive treatment with Isomate-C r , illustrates just how ineffective mating disruption of codling moth is when the density of the overwintering population is unknown and uncontrolled. Studies carried out in the early part of this century (Chandler, 1928;Steiner, 1929;Newcomer et al, 1933;Steiner & Ackerman, 1936) showed that while 50% of the overwintering larvae were caught in properly used bands, orchards still sustained 50-65% damage, as did our reference orchard (Table 3). The number of overwintering larvae found in orchard A-3 in 1989 (Figure 2), before mating disruption was implemented, indicates that cultural techniques (see introduction) were at best maintaining population densities at levels comparable to those found in our banded experimental orchard in 1990.…”

“…However, while commercially unacceptable levels of damage are often seen in organic orchards employing pheromone-based mating disruption (Knight, 1994;Trimble, 1995), or tree banding (Steiner & Ackerman, 1936) alone, these control measures can have considerable impact on the population density of codling moth. Newcomer et al (1933) found that 50% of an overwintering codling moth population can be trapped in properly used tree bands and Judd & Thomson (1990) estimated it may be as high as 65% on smooth-barked varieties in high density plantings in British Columbia.…”