Minor components modulate sensitivity to the pheromone antagonist Z11-14:Ac in male lightbrown apple moth, Epiphyas postvittana (Lepidoptera: Tortricidae) in the field

Epiphyas postvittana is a major horticultural pest in many countries, including New Zealand. Recently, two minor components (E)-11-tetradecen-1-ol and (E)-11-hexadecenyl acetate were found to increase the attraction of a previously identified two-component sex pheromone (95:5 blend of (E)-11-tetradecenyl acetate [E11-14:Ac] and (E,E)-9,11-tetradecadienyl acetate [E9,E11-14:Ac]) of Epiphyas postvittana. We hypothesised that the interaction between these minor components and the behavioural antagonist (Z)-11-tetradecenyl acetate (Z11-14:Ac) would modulate its antagonistic effect. The effect of increasing the ratio (0.5—10%) of Z11-14:Ac was tested in traps baited with E11-14:Ac and E9,E11-14:Ac (95:5), with or without the addition of the two minor compounds. Catch decreased as the percentage of Z11-14:Ac increased (χ2=108.74; d.f.=9; P<0.001). Overall, more moths were caught in traps baited with four- vs two-component lures (χ2=9.81; d.f.=1; P=0.002); in pair-level comparisons, significant differences in catch number between the two- and four-component lures were observed when the E11-14:Ac : Z11-14:Ac ratio was 99:1 (P=0.031) or 98:2 (P=0.047). The addition of the two minor components mitigated the reduced catch effect due to lower proportions of E11-14:Ac and the presence of 1—2% antagonist.

The relationship between Epiphyas postvittana (lightbrown apple moth, Lepidoptera: Tortricidae) in pipfruit orchards and adjacent vineyards in Nelson

The lightbrown apple moth (Epiphyas postvittana) is the most abundant leafroller species infesting apple orchards and vineyards in the Nelson region. This study was undertaken to investigate concerns from some orchardists of leafroller pressure on their apple blocks adjacent to neighbouring vineyards. Lightbrown apple moth pheromone trap catches were recorded inside orchards and in neighbouring vineyards and in boundary rows of the orchards closest to a vineyard during 2012—13. The vineyards were not treated with insecticide and the orchards received ve applications of insecticide between November and mid- March to control lepidopteran pests. The highest catches of leafrollers were recorded in vineyards and catches increased during the season to peak in April. The increasing leafroller population in vineyards was associated with higher catches of leafrollers in boundary rows of the orchard closest to the vineyard. Leafroller catches inside the orchards were lower while insecticide sprays were being applied. The higher pheromone trap catches of leafrollers in the vineyards and on the orchard boundary were associated with the most leafroller sign that was found in these locations during timed searches. These results suggest that high populations of leafrollers in vineyards can increase leafroller pressure on nearby pipfruit orchards.

Parasitoids of leafrollers (LepidopteraTortricidae) from scrub vegetation near horticultural areas in Nelson

Leafroller larvae and pupae were collected during timed searches in January and April 2013 from host plants at six scrub vegetation sites in two Nelson horticultural districts approximately 40 km apart The numbers of leafrollers and parasitoid species recovered were similar in both districts Most of the leafroller larvae collected were Epiphyas postvittana (Walker) (lightbrown apple moth LBAM) and most of these were found on gorse and broom In total 293 larvae and 11 pupae were reared successfully with 39 parasitism A wide diversity of parasitoids was recovered comprising 10 species from five families with Dolichogenidea tasmanica (Braconidae) the most common (80) The diversity of parasitoids and parasitism of leafrollers in unmanaged environments outside orchards may help to reduce leafroller pressure and the risk of fruit infestation in surrounding commercial orchards

Olfactory responses of Epiphyas postvittana larvae to apple leaf extracts a new behavioural bioassay technique

Epiphyas postvittana (lightbrown apple moth LBAM) is a polyphagous pest of horticulture native to Australia and introduced into New Zealand New Caledonia the British Isles Hawaii and California Olfactory responses of LBAM have been well studied but this has mostly been confined to adult moths In this study olfactory responses of LBAM larvae to apple leaf extracts were measured using a new laboratory bioassay technique for choice tests Apple leaf extracts were prepared using four different extraction methods methanol soak near boiling water dip chloroform soak and 70 ethanol blended The choice of larvae between an apple leaf extract and solvent control was examined and the bioassays were videorecorded in timelapse mode with an infraredenabled camera LBAM larvae were significantly attracted to some of the apple leaf extracts The results indicate that the new bioassay method can be used as a reliable tool for evaluating the olfactory attraction of LBAM larvae and most likely also of many other species Based on these findings an attempt will be made to identify the active compounds present in the apple leaves that are responsible for the larval attraction

Control of Epiphyas postvittana (lightbrown apple moth Lepidoptera Tortricidae) on grapevines with tebufenozide

Feeding by leafroller larvae damages grape bunches and makes them susceptible to Botrytis cinerea disease Leafroller infestation of foliage and bunches and the incidence of botrytis was measured on vineyards in Gisborne Hawkes Bay and Marlborough over 2 years Fortyfour blocks received no leafrolleractive insecticides while 22 were sprayed once preflowering with the selective insect growth regulator tebufenozide Tebufenozide very effectively reduced infestations and gave seasonlong control On leaves untreated blocks averaged 14 leafrollers/search compared with 4 on sprayed blocks Comparative figures for fruit at harvest were 18/100 bunches and 3/100 respectively There was a trend for lower botrytis incidence in blocks where tebufenozide was used Over 99 of the leafrollers reared were Epiphyas postvittana Parasitism of larvae and pupae at 67 on leaves and 50 in bunches was similar in untreated and treated blocks Epiphyas postvittana in vineyards is easily managed using tebufenozide which did not compromise biological control

The potential of using low oxygen and ethyl formate or ethyl acetate to disinfest fresh fruit in storage

Low oxygen and/or generally recognised as safe (GRAS)/food additive (FA) treatments in combination with cool storage have the potential to disinfest a range of commodities of various pests This paper reports on research to determine the tolerance of second/third and fifth instar codling moth larvae fifth instar lightbrown apple moth larvae mixed stages of greedy scale and obscure mealybugs and diapausing twospotted mite adults to ultra low oxygen (ULO lt;05 O2) and ULO combined with two GRAS/ FA compounds ethyl acetate and ethyl formate ULO alone did not consistently enhance mortality of these pests compared with air cool storage However addition of 30005000 ppm of ethyl acetate or ethyl formate reduced the time taken to achieve 99 mortality from weeks or months to between 8 h and 5 days depending on the pest

Development of multiple species mating disruption to control codling moth and leafrollers (Lepidoptera Tortricidae)

Codling moth (Cydia pomonella) and leafrollers principally lightbrown apple moth (Epiphyas postvittana) are key pests of apples Pheromone mating disruption has until now required separate dispensers to be deployed for each pest group With 6001000 dispensers per ha for each species application costs are a significant factor limiting the wider adoption of multispecies mating disruption in New Zealand apple orchards The aim was to integrate the two disruption systems into a single dispenser and evaluate its performance against that of separate dispensers in paired block comparisons on four apple orchards The three measures of effectiveness pheromone trap catch suppression of moth mating and fruit damage at harvest all showed no statistical differences between the two treatments The performance of the new combination pheromone dispenser was equivalent to that when the two dispensers were deployed separately