Abstract
Mites from an abandoned olive nursery in Egypt were observed for two years, during which species diversity, seasonal fluctuations and biological aspects of specific eriophyid species were studied. Two eriophyid species - the olive bud mite Aceria oleae Nalepa and the olive rust mite Tegolophus hassani (Keifer), representing a basic trophic level - were fed upon by two predacious mites - Neosciulus cydnodactylon (Shehata and Zaher) and Agistemus olivi Romeih. Population abundance of the eriophyid mites was affected by climatic conditions, predation, shady and sunny zones, leaf age and vertical distribution. About 12, 5, 15 and 4 generations were recorded for both eriophyid species during the two successive years, respectively. A control measure of one spring pesticide (abamectin) seemed to be the most successful against the harmful mites. Life table parameters showed that the population of T hassani multiplied 9.92 times in a generation time of 14.42 days at 31 degrees C and 80 % r. H., while the A. oleae population increased 16.70 times in a generation time of 13.50 days at the same conditions. Field and laboratory studies indicated that the olive bud mite is considered to be a disastrous mite on shrub and young olive trees.