Control of multiple species of lepidopterous insect pests using a mating disrupter and reduced pesticide applications in Japanese pear orchards.

Efficacy of a mating disrupter against multiple species of lepidopterous in sects was tested in Japanese pear orchards in Tottori, Japan during 1997, w ith the goal of reducing the amounts of insecticides and acaricides applied . Three experimental plots were set up as follows: (1) conventional control plots in which insecticides and acaricides were sprayed 14 times; (2) trea tment with the mating disrupter, "Confuzer-p(R)" and application of insecti cides reduced to 20% of the conventional control (Plot 1); and (3) use of t he mating disrupter and 35% of the conventional control insecticide applica tion (Plot 2). The mating disrupter seemed to be effective against Homona m agnanima, Adoxophyes honmoi and Carposina niponensis in terms of the number of male moths caught in the sex pheromone trap and the percentage of injur ed fruit. Reduced applications of insecticides conserved to some degree the predators of spider mites, especially the predaceous thrips, Scolothrips t akahashii. Acaricide application was therefore reduced to one time in Plot 1 and none in Plot 2 as compared with twice in the conventional control plo t. The occurrence of minor insect pests, Eumeta japonica, Ascotis selenaria and Euproctis spp., tended to increase in Plots 1 and 2. These insects inj ured the pear shoots, although injury to the fruit was negligible. The cost of the control measures in Plots 1 and 2 was around 1,400 US dollars per h a as compared with 1,300 dollars in the conventional control plot.