Apple foliage enhances mating disruption of light-brown apple moth

Abstract

Uptake and release of pheromone and behavioral inhibitor ofEpiphyas postvittanna by apple leaves was tested using field electroantennograms (EAG), trap catches to synthetic lures and virgin females, and chemical analysis. Trap catches in single apple trees (N=3) were monitored for six cycles of six days' duration, using delta traps baited with synthetic pheromone. Polyethylene dispensers (0, 1, 10 per tree) releasing pheromone and inhibitor were present for only the first three days of each cycle. Application of 10 dispensers per tree resulted in complete disruption of trapping, which continued for one day after dispensers were removed. Over the three nights following the removal of the dispensers (days 4-6), trap catch was 0, 10, and 15% of the control catch. In contrast, the presence of only one dispenser per tree led to 0-20% of control catches, but on the three nights following dispenser removal catches were 35, 40, and 80% of the control catch. Field EAGs indicated significantly higher relative pheromone concentrations in the trees with 10 dispensers present, compared to trees with single dispensers, but removal of dispensers produced no detectable treatment effect compared to the control trees one day after dispenser removal. In a second experiment, releases of marked male moths into apple orchard plots following the removal of polyethylene dispensers (1 hr earlier that day) resulted in significantly lower catches in traps baited with virgin females in blocks that had been treated, compared to controls. Recovery of pheromone by solvent washing of leaves loaded with 50 µg of the main component of the sex pheromone (1.26 µg/cm(2)) was low (2.5%). Leaves held in a pheromone-saturated atmosphere were loaded with 0.045±0.007 µg pheromone/cm(2). Analysis of apple leaves taken from a pheromone-treated tree at different distances from the pheromone dispenser showed a decay of the pheromone load per square centimeter with increasing distance from the dispenser, as previously indicated by EAG.

Development of single‐dispenser pheromone suppression of Epiphyas postvittana, Planotortrix octo and Ctenopseustis obliquana in New Zealand stone fruit orchards

“…Pre‐exposure of moths to sex pheromone reduced male moth sexual responsiveness in E. postvittana ,28–31 and the present wind tunnel trials after pre‐exposure corroborated this effect with a new method. This physiological and behavioural response contrasts with P. octo , where results confirm that a more rapid recovery of response took place after pre‐exposure, compared with the other two species.…”

Field electroantennogram and trap assessments of aerosol pheromone dispensers for disrupting mating in Epiphyas postvittana

“…The behavioural inhibitor is a byproduct of the manufacture of the commercialised product, rather than a deliberate addition. The blend tested in the aerosol formulation was the natural pheromone blend,11 while the polyethylene tubing dispensers released an off‐ratio blend3 that has been commercialised in New Zealand and more recently in Australia. Both dispensers were operated at ca 1.5 m above the soil surface.…”

“…Prospects for more sustainable apple production in New Zealand would be enhanced by the more cost‐effective use of sex pheromones for mating disruption of leafrollers. Mating disruption should assist insecticide resistance management1, 2 and leafroller pest management by decreasing dependence on insecticides 3. The release rate of most pheromone dispensers is driven by temperature, with the highest release rate during the middle of the day.…”

Sex Pheromones and Their Impact on Pest Management

“…Suckling and Clearwater (1990) demonstrated that a 2-component blend provided better communication disruption than the main compound alone. Mating disruption then was conceived as a strategy to achieve, in combination with a reduced spray program, economically acceptable control in insecticide resistant populations in apple in New Zealand Suckling and Shaw 1995). More recently, efficient population control has been demonstrated in Australian citrus (Mo et al 2006).…”