Caterpillars of the crown fauna in stands of substitute tree species

Abstract

We studied the crown fauna of caterpillars in the air-polluted area of the Krušné hory Mts, in tree stands consisting of substitute tree species Betula pendula Roth, Sorbus aucuparia L., Alnus alnobetula (Ehrh.), Picea pungens Englm., Pinus sylvestris L., Larix decidua Mill., Acer campestre L., Pinus sylvestris L., Fagus sylvatica L., Quercus robur L. and Q. rubra L. We used the method of shaking off the crown fauna of caterpillars. In the course of two years, larvae of 137 Lepidoptera species were registered, namely 123 species on broadleaved trees and 27 on conifers. Birch (63 species), alder (54) and mountain ash (38) showed the richest crown fauna. The proportion of caterpillars in the crown of beech (24), larch (18) and oak (25) was, however, poorer in species. Paraswammerdamia albicapitella (Scharf.) was found only on mountain ash, Aleimma loeflingianum (L.) on red oak and Ypsolopha ustella (Cl.) on sessile oak. The occurrence of caterpillars on Picea pungens is surprising because it represents a very unattractive species for phytophages and information is missing on its fauna from the area of the CR. Soerensen's index of faunistic similarity was highest between birch and alder (51.3%) and the same level of similarity was noted between birch and mountain ash (31.7%) and beech (32.2%) and oak (26%).