A comparison of sampling techniques for spider mites and spider mitepredators in corn

摘要

Three techniques for sampling spider mites (Acari:Tetranychidae), predatory mites (Acari: Phytoseiidae), and other predacious arthropods in field corn (Zea mays L.) were evaluated in southwestern Kansas in 1996. Samples were taken at five sample sites in eight fields on four sample dates. In the two fields in which all three techniques were used, there were significantly greater numbers of spider mites, phytoseiids, and other predacious arthropods in the samples processed using the Berlese funnel procedure than in samples processed as visual plant counts or with the leaf brushing machine. In the eight fields in which two of the techniques were tested, there were significantly greater numbers of phytoseiids and other arthropods recovered with the Berlese funnel procedure than in samples processed as visual plant counts. However, the number of spider mites did not differ significantly for the two techniques. These results indicate the Berlese funnel procedure was the most effective sampling technique for the recovery of phytoseiids. It was also at least as effective as visual plant counts for the recovery of active stages of spider mites.