Mating disruption for the control of leafrollers on apricots

Abstract

Otago apricots (Prunus armeniaca L.) are damaged by the endemic leafroliers, Planotortrix octo Dugdale and Ctenopseustis obliquana (Walker), and an Australian species, Epiphyas postvittana (Walker), all of which are quarantine pests on export fruit. Mating disruption, using sex pheromones, represents one promising option for pest management with reduced insecticidal inputs for apricots. Two pheromone blends were used: one, designed to disrupt the two endemic species, was (Z)-5-tetradecenyl acetate and (Z)-8-tetradecenyl acetate, (25:75) and the other, for E. postvittana, was (E)-1 1tetradecenyl acetate and (E)-9,(E)-11-tetradecenyl-1 acetate (95:5). No moths of three leafroller species were caught in pheromone traps at the centre of 0.1 ha plots of apricot trees treated with polyethylene tubing dispensers, at 1000/ha, whereas those outside the treated area (70 m distant) continued to catch. In commercial orchards, dispenser blends prevented trap catch and reduced damage in apricots on 1-3 H97062

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

“…Another difference between the conditions in the present experiments and those reported from California6, 7 is the higher insect density encountered in the present experiments; this could play a role in the outcome, since disruption of catch and mating is more effective at low insect densities 19. The lack of complete inhibition of catch of E. postvittana in the orchard treatment with 1000 polyethylene dispensers per hectare is in contrast to results in other regions of New Zealand, where the dispensers have been deployed successfully for reducing catch and fruit damage 3, 20…”

“…19 The lack of complete inhibition of catch of E. postvittana in the orchard treatment with 1000 polyethylene dispensers per hectare is in contrast to results in other regions of New Zealand, where the dispensers have been deployed successfully for reducing catch and fruit damage. 3,20 The blend tested in the aerosol formulation was the natural pheromone blend, 11 while the polyethylene tubing dispensers released an off-ratio blend, which has been commercialised. 3 The natural blend in the aerosols was used to give the aerosol formulation a better chance of success, as the mechanism of disruption could then have involved the following of false trails as well as habituation, 21 and the off-ratio blend was unlikely to be any better than the natural blend.…”

Communication Disruption of <I>Epiphyas postvittana</I> (Lepidoptera: Tortricidae) By Using Two Formulations at Four Point Source Densities in Vineyards

“…These three formulations were successful in causing high levels of trap shutdown, which indicates they are likely to successful for control in environments such as vineyards, based on previous work in tree fruits showing reduced larval incidence and damage (Suckling and Shaw 1995, McLaren et al 1998, Mo et al 2006. Mating disruption has long been employed in European vineyards against European grapevine moth Lobesia botrana (Denis & Schiffermü ller), where it was clear that the foliage canopy had an important role in maintaining atmospheric concentrations (Sauer and Karg 1998).…”

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

“…P. octo and C. obliquana ) was then demonstrated to be feasible with a single blend of two components, based on their overlapping pheromone communication systems 5, 20. Mating disruption of the three leafroller species using two separate dispensers ( E. postvittana or P. octo plus C. obliquana ) was used to produce stone fruit with reduced insecticide inputs,21 building on success in apples against E. postvittana 22. However, adoption of the two dispensers21 was uneconomic compared with an insecticide programme owing to labour costs, and consequently there was a lack of market demand for the technology in stone fruit at that time (unpublished data).…”

“…Although many cases have been recorded of disruption using natural blends where false trail following might apply,23 this disruption mechanism is not possible where blends are unattractive because they are incomplete or contain antagonists 24. Two New Zealand species ( P. octo and C. herana ) were successfully disrupted with off‐ratio blends containing only unattractive (incomplete) pheromones or behavioural antagonists 5, 21. Recent consideration has focused on competitive attraction for insects such as codling moth ( Cydia pomonella ), where the single‐species disruptant is attractive 25.…”