Outbreak, intensity of infestation and control of two new Eriophyids, Aceria oleae and Ahevtchenkella barensis, on olive nursery plants in Montenegro

摘要

Only two species of eriophyoid mites, Ditrimacus athiasella Keifer and Oxycenus maxwelli (Keifer), have been registered in Montenegro until recently. Late in April 2007, chlorotic spots and deformations were found on apical leaves of one-year old seedlings of the ?utica variety in a greenhouse in the town of Bar. Two species of eriophyoid mites were identified from the collected material, Aceria oleae, a widely distributed species in Mediterranean countries, and Shevtchenkela barensis, described as a new species in the world acarofauna. The intensity of infestation was calculated from all visually examined seedlings (2,560), as well as the percentage of seedlings with observed symptoms. Applying the method of periodic sampling, 50 seedlings (2 % of the total number) were chosen. The intensity of injury was estimated on the new growth. Of the total number of examined seedlings, obvious symptoms were detected on 61.45% of the plants. Of the 50 chosen seedlings, 56 % had all of their young leaflets injuried. Mite control was applied three times. After the third treatment, new leaves without symptoms emerged, while untreated seedlings stopped to grow, their injuried leaves fell off and the seedlings ultimately dried out completely.