Monitoring pests of peaches in Hawke's Bay to reduce insecticide applications.
The tortricids Epiphyas postvittana, Planotortrix octo, Ctenopseustis obliquana and Cydia molesta [Grapholita molesta] and the aphid Myzus persicae, were monitored with pheromone traps and by counts on shoots and fruit, in 4 peach cv. Golden Queen orchards in Hawke's Bay, New Zealand, during 1994-95. Insecticides were applied only when pest thresholds were exceeded. The thresholds used were: >16% trees infested for M. persicae; 8/trap per week for G. molesta; and >8% of trees infested until December and then >2% of fruit infested for the other tortricids. Insect damage on fruit at harvest from all the blocks was within acceptable levels for process peaches. Excluding clean-up sprays, the monitored blocks averaged 1.2 insecticide applications during the season compared with the district average of 3.4 applications. The industry average in Hawke's Bay between 1990-91 and 1994-95 was 4.0 insecticide applications per season, with up to 13 applications per season on some orchards.