Woolhouse, M.E.J., Harmsen, R., 1984.
The mite complex on the foliage of a pesticide-free apple orchard: population dynamics and habitat associations. Proceedings of the Entomological Society of Ontario, 115: 1-11.
Abstract
The population dynamics of the mite complex inhabiting apple foliage in an orchard in southern Ontario was studied in 1982-84. Nine common species are listed, dealt with, the trophic relationships between pests (especially the tetranychids Tetranychus urticae and Panonychus ulmi and the eriophyid Aculus sp.), predators (especially the stigmaeid Zetzellia mali, the phytoseiids Amblyseius fallacis and Typhlodromus spp. and the erythraeid Balaustium sp.) and others (scavengers and fungivores) being shown in a diagram. The population dynamics varied from year to year, but at no time did pest species reach economic thresholds. Populations of Z. mali and phytoseiids followed the changes in prey abundance, Z. mali was more closely linked to eriophyid abundance, and phytoseiids to tetranychid abundance. Certain species were more abundant on particular varieties of apple, but these differences were not always consistent from year to year. Z. mali and phytoseiids were most abundant nearest the edge of the orchard. In the absence of pesticides (except fungicides) arthropod pests caused few problems. The implications of the findings for pest management are discussed.
