Developing a monitoring programme for insect pests of stonefruit in Canterbury

Abstract

An insect pest monitoring programme was developed for export peaches and nectarines in Canterbury. Pest colonisation of a recently planted orchard was also assessed.

Monitoring was carried out on the Lincoln Springs orchard Canterbury, New Zealand, from August 1985 to May 1986. Thrips obscuratus adults were trapped weekly using white painted water traps. Males of Epiphyas postvittana (Walker), Ctenopseustis 'iniana' (Walker) and Planotortrix excessana (Walker) were trapped using species specific pheromone traps. Port wine bait traps were used to trap female leaf rollers. Myzus persicae (Sulzer) were sampled twice weekly on leaf tips in spring. Panonychus ulmi (Koch), Tetranychus urticae (Koch) and associated predator mites were sampled using 50 leaf samples per block, based on apple Integrated Mite Control sampling procedures. Costelytra zealandica (White) adult flights were trapped nightly in pheromone traps. Two hundred nectarine and peach fruit were examined at harvest for thrips and leaf roller damage.

Thrips trap catches were low at flowering and harvest when most damage occurred, therefore water traps were too insensitive. Ulex europeus appeared to be a likely infestation source. Epiphyas postvittana was the only leafroller species caught. The initial flight peak was comparable to other reports but then differed. Port wine traps were unreliable. The sample unit for Myzus persicae proved useful but omission of a winter oil spray meant the sampling needs repeating. The only mite to appear was Tetranychus urticae which did not build up to significant levels. Costelytra zealandica did not appear to significantly damage the fruit trees. Thrips russet damage on two nectarine varieties meant 54% or 78% of fruit was rejected for export. Thrips presence on both peach and nectarine at harvest could be a serious quarantine problem.

Further development of individual pest monitoring systems is required before an integrated orchard monitoring system can be developed.