In a research project investigating the contribution of forest ecotone structures to regional arthropod biodiversity, the neuropteran fauna was assessed at five differently-structured forest edges and, for comparison, 50 m inside the forest. Arthropods were collected from February to November by means of pitfall traps, window (interception) traps and yellow water pans. The traps were installed along transects, reaching horizontally from the open cultivated land into the forest and vertically, oil scaffolds. from the ground LIP to the tree crowns.
For each of the species of the insect orders Ncuroptera (59), Raphidioptera (3) and Mecoptera (2), spatio-temporal distribution patterns from open habitats into the forest call be generated from the available database. Only 3 species (5%) were equally or more numerous inside the forest than at the edges. Of particular interest is the distribution in space and time of three sibling species of the Chrysoperla carnea complex (C. lucasina, C. pallida, C. carnea).
Neuroptera and Raphidioptera showed their highest species numbers in the shrub belt and the forest mantle, while the Mecoptera preferred the herbaceous fringe. Traps located deepest inside the forest yielded the lowest number of species. In the forest interior, species numbers peaked in the canopy. However, the canopy yielded markedly fewer species than the forest edges. Steep forest edges contained 24% more species than the forest interior, sloped, structurally rich forest edges even 60% more.