Gamasina communities (Acari, Parasitiformes) of arable soils with two different soil types

During 1991-1993 Gamasina communities were investigated in two agricultural areas in East Slovakia: the East-Slovak Lowland and the Kosice Basin. The study was carried out in cultivated fields on two different soil types: alb ic luvisol and eutric fluvisol, which were each replicated at six sites and sampled at two-month intervals. Species richness of Gamasina varied betwee n 11-26 species and significantly correlated with content of organic carbon in the soil. Arctoseius cetratus, Alliphis siculus and Rhodacarellus siles iacus were dominant species at sites. Abundance of assemblages was generall y low, nor having a significantly higher mean value on the eutric fluvisol (280 ind. m(-2)) compared to the albic luvisol (230 ind. m(-2)). The result s from cluster and ordination analysis of quantitative data showed no effec t of soil type, composition of Gamasina assemblages being more affected by geographical area or particular site. Populations of Pachylaelaps pectinife r, Alliphis siculus and Eugamasoidea nymphs correlated significantly with s andy mineral content in the soil.