Acta Zoologica Cracoviensia, 15() 1970
Migrations and Wintering of Cassids (Coleoptera, Chrysomelidae, Cassidinae) under the Climatic Conditions of the Ojców National Park
Abstract:
In 1966-1967 a study of 4 species of cassids — Cassida rubiginosa Müll., С. vibex L., G. viridis L., G. flaveola Thunbg. — was carried out in an area selected in a meadow of Arrhenatheretum elatioris in the Sąspowska Valley. The numbers of adult and young specimens of these beetles were noted in successive periods of investigation. In 1967 the marking and recapturing of the cassids under study were also applied. Young beetles were found to stay in the meadow from 2 weeks to 2 months, next, towards the end of the summer and in the autumn, they migrated to a hornbeam forest on the southern slope of the valley, where they wintered, exclusively in the adult stage and in diapause, at a depth of 5-8 cm under the litter. The microclimatic measurements taken in the autumn of 1967 and in the winter of 1968 showed that cassids find more favourable conditions for hibernation in the forest than in the meadow. Thirty-three wintering specimens belonging to 6 cassid species (Cassida rubiginosa Müll., C. vibex L., C. viridis L., C. flaveola Thunbg., C . hemisphaerica Herbst and C. nobilis L.) were found in 320 samples of litter. The re-emigration of the adult beetles from the forest to the meadow takes place in the spring and ends in the first days of July.
