Abstract
The species composition of predators of spider mites was monitored by using kidney bean traps infested by spider mites that were placed on the ground around the chrysanthemum fields in Heguri, Nara Prefecture. The predominant phytoseiid mite species captured by the traps was Neoseiulus womersleyi. The next abundant predacious insect species was Feltiella sp.
In the chrysanthemum fields infested by spider mites at a low density, no phytoseiid mites were found. In the fields frequently sprayed with chemicals that affected phytoseiid mites, phytoseiid mites were rarely observed even when the density of the spider mites on the chrysanthemums increased. However, in the field sprayed with chemicals only a few times, the number of phytoseiid mites increased when the spider mite density increased resulting in a decrease in the spider mite density.
The phytoseiid mite, Neoseiulus womersleyi was found in the chrysanthemum field that was not sprayed with chemicals for more than 2∼3 weeks after harvest and where the occurrence of spider mites was observed.
