Mite species (Acari) on blackberry cultivars in organic and conventional farms in Florida and Georgia, USA

Summary

This study was carried out to determine mite species on blackberry plants (Rubus spp. (Rosaceae)) in Florida and Georgia, USA, and differences in mite species between organic and conventional blackberry plantings in the area sampled. Surveys were conducted in organic and conventional commercial blackberry plantings from June to October 2016. Leaf samples were collected monthly from nine different blackberry cultivars including ‘Arapaho’, ‘Choctaw’, ‘Freedom’, ‘Kiowa’, ‘Natchez’, ‘Navaho’, ‘Osage’, ‘Ouachita’, and Von. Approximately 20 leaves per blackberry plant were taken. Twenty mite species (a total of 152 mite specimens) belonging to 7 families including Phytoseiidae (9 species), Ascidae (1), Cheyletidae (1), Erythraeidae (1), Stigmaeidae (1), Tetranychidae (4) and Tarsonemidae (3) were identified during the study. It was found that the abundance of predatory mites collected in organic farms was over 2-fold higher (105) than in conventional farms (47), which may be related to pesticide use on these commercial farms. Future surveys should provide a list of predatory species, which may hold potential for biological control of economically important pest mites.