Vertical distribution of codling moth adults in pheromone‐treated and untreated plots

Abstract

The vertical distribution of codling moth, Cydia pomonella (L.) within pheromone‐treated and untreated apple and pear orchard canopies was determined using tethered virgin females, unbaited sticky traps, and blacklight observation of released moths. Mating of virgin females tethered at various heights in untreated orchard canopies increased with placement height from 1–4 m. Application of pheromone dispensers for mating disruption at 2 and 4 m above the ground greatly decreased mating. Greatest capture of males and females on unbaited sticky traps occurred at mid‐ and upper‐canopy heights. Total capture of males and females in pheromone‐treated plots was not statistically different than in untreated plots. The percentage of mated females captured on sticky traps did not vary with trap height or pheromone treatment. Released moths marked with fluorescent powder and observed at dark with a blacklight indicated that moths are primarily distributed high in the canopy. However, males shifted to a position lower in the canopy when pheromone dispensers were placed 2.1 m above the ground. Results suggest that pheromone dispensers be placed in the upper canopy for optimal disruption of codling moth mating.

Oviposition and Calling Behavior of Codling Moth (Lepidoptera: Tortricidae) in the Presence of Codlemone

“…Codling moth females are active, and mate most frequently in the upper canopy (Weissling and Knight 1995). Therefore, mating disruptant dispensers applied low in the canopy may not sufficiently mask a potentially competing female.…”

“…Codling moth mating generally occurs high in the orchard canopy (Weissling and Knight 1995) and is entrained to photoperiod, normally taking place during evening twilight (reviewed in Howell 1991). Calling females assume a characteristic position on tree branches or leaves, and release pheromone primarily during the scotophase (Niemczyk et al 1977, Castrovillo andCarde 1979).…”

High versus ultra-low volume spraying of a microencapsulated pheromone formulation for codling moth control in two apple cultivars

“…On the other hand, high speed low-volume application targeted the larger spray droplets containing up to 0.38 microcapsules per cm 2 into the upper canopy. The use of low-volume application is therefore likely to increase the efficacy of mating disruption because codling moth adults prefer to fly in the upper canopy where most oviposition and damage occurs (Weissling and Knight 1995).…”

Codling moth areawide integrated pest management.

“…This orchard had a number of poor characteristics that lessened the likely success of MD: a high initial population of CM, a 6% slope, a high proportion of missing trees and an uneven orchard canopy (tree heights ranged from 2 to 5 m). Specific studies addressing the optimal use of the Isomate-C dispenser for CM MD -such as characterizing the seasonal dispenser emission rate, the influence of dispenser density and positioning within the canopy and the role of sex pheromone blend -were not sufficiently characterized until 1995 (Knight, 1995b;Knight eta!., 1995;Weissling and Knight, 1995).…”