Effect Of Ploughing And Pesticide Application On Oribatid Mite Communities

The impact of conventional pesticide treatment and deep ploughing on oribatid mite communities was investigated in an abandoned arable land. The experimental plots were divided in pesticide and ploughed (PPL), ploughed (PL) and a meadow as control (Ctr). Soil samples were taken monthly during the vegetation period (March-August) and once in three months (October and January) in a period without vegetation. Seventy-seven species of oribatid mites were determined. Species numbers were highest in Ctr (55 species), lower in PPL (53) and lowest in PL (41). Oribatid communities were dominated by sexually reproducing Brachypylina. Some of the generally frequent parthenogenetic species (e.g. Acrotritia ardua and Oppiella nova) were rare at the Ctr sites while stress-tolerant species (both, sexual and asexual, e.g. Protoribates capucinus, Punctoribates punctum, Ramusella clavipectinata, Tectocepheus velatus) were dominant. Pesticide application did not show any effect on oribatid mite community beyond the ploughing, whereas some species likeP. capucinus, P. punctum, R. clavipectinata and T. velatus reached high abundances at PPL sites. Community structure of oribatid mites did not change significantly compared with Ctr sites, suggesting that the study area is inhabited by stress tolerant oribatid communities shaped by past agricultural disturbance.