MONITORING LEAFROLLERS (LEPIDOPTERA: TORTRICIDAE) IN VINEYARDS

摘要

Leafroller larvae, especially Epiphyas postvittana, damage grape bunches, and more importantly promote spread of the disease botrytis (Botrytis cinerea). Three methods of monitoring leafrollers were compared on 10 Hawke's Bay vineyard blocks. The methods were timed searches of leaves for larvae, inspection of bunches for larvae, and pheromone trapping of adult males. Seasonal changes in leafroller abundance were similar on all vineyards. Usually few larvae were found until February, but infestationsincreased greatly between then and March. In other respects, leafroller infestations were variable between and sometimes within blocks. None of the monitoring methods was completely successful. The most useful method was bunch inspection, primarily because of the close correlation between bunch infestations in January and at harvest. However, this method is relatively laborious and did not give enough warning to enable use of some insecticides. Leafroller infestations on leaves in all months and pheromone trap data were poor predictors of harvest bunch damage.