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

Abstract


 
 
 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.