Epigaeic weevils (Coleoptera, Curculionoidea) of oak-hornbeam forests in a vicinity of Bratislava (SW Slovakia)

In 1999-2000, we studied the weevil assemblages in the epigaeon of oak-hornbeam forests in the Male Karpaty Mts., SW Slovakia, with regard to assemblage structure, species richness, number of individuals, topic and trophic requirements as well as habitat and moisture preference in particular species. The weevils were collected by sifting the litter, surface layer of soil and remnants of twigs at five study sites affected by human activities. The trees growing at these sites were 40-100 years old. We recorded a total of 44 weevil species classified within 28 genera and 3 families. The number of species found at particular sites ranged from 17 to 26. The mean abundance (density) of weevils varied from 5.8 to 23.9 ind.m-2 of the soil surface. The geobionts Barypeithes chevrolati, Acalles echinatus and A. commutatus were the predominating species. The abundance dynamics of weevils showed two distinct peaks. The first peak observed in April or May was followed by the second peak in August or September, respectively. Typical geobionts within the genera Barypeithes and Brachysomus largely shared in the abundance maximum in the spring. The high proportion of saproxylic species belonging to the genera Acalles and Ruteria significantly contributed to the abundance maximum in the late summer and in the autumn. The weevil assemblages were characterized by the high share of stenotopic, hygrophilous, geobiont, polyphagous, saproxylic and apterous (non-flying) species. European (34 %), Holarctic (18 %) and Palaearctic (16 %) species were the most frequent. Several records of weevil species, namely those of Kyklioacalles suturatus, Stomodes gyrosicollis, Simo variegates, Brachysomus dispar, Trachyphloeus scabriculus, are of faunistic interest.