Predominance ofVibidia duodecimguttata (Poda, 1761) in the assemblages of ladybird beetles (Coleoptera: Coccinellidae) overwintering in floodplain forests

We investigated assemblages of ladybird beetles overwintering in the litter of willow-poplar floodplain forests (Salici-Populetum) that grew along the banks of the river Vistula in the Mazovian Lowland (central Poland). Altogether, in six study sites, 14 ladybird pecies were recorded, of which the very clear dominant was a rare mycophagous species, Vibidia duodecimguttata. Its contribution to all Coccinellidae sampled in early dormancy period (November-December) was 81% and to those sampled in late dormancy period (March-April) - 76%. Total numbers of ladybirds and the numbers of V. duodecimguttata sampled in individual sites were negatively related to the soil humidity in these sites. Degree of the forest degradation expressed as the coverage of sampling sites by a non-native tree, Acer negundo, was not found to affect the abundance of the beetles. The rate of winter mortality of V. duodecimguttata was relatively low, accounting for 12.2% for pooled data from the six sites.