THE RESPONSE OF HETEROPTERA AND COLEOPTERA SPECIES TO SHADE AND ASPECT IN RIDES OF CONIFERISED LOWLAND WOODS IN SOUTHERN ENGLAND

The relationship between shade and aspect and the species richness and abundance of Heteroptera and Coleoptera (Chrysomelidae and Curculiono idea) was examined in the rides of coniferised ancient woodlands. A to tal of 83 species of Heteroptera, and 31 and 58 species of Chrysomelid ae and Curculionoidea respectively, were identified from samples taken from nine woodland sites in southern England Shade, both direct and i ndirect, was measured by hemispherical photography. Regression models for each insect group related species richness and abundance to shade and inherent wood differences. Indirect shade was at least as good a p redictor as direct shade. Both species richness and abundance declined with increasing levels of shade. Shrub-associated Heteroptera appeare d in general to be more shade-tolerant than herb-associated species. T he opposite was true for the Coleoptera, but numbers were generally sm all. Some significant relationships with aspect were found with severa l species showing an apparent preference for south-facing aspects. The results of this study support the conclusion from studies on butterfl ies, namely that rides must be actively managed to keep light levels h igh if species richness and abundance are to be maintained.