Beetles and flies of various tree species (Insecta: Coleoptera et Diptera).

On a "Day of Biodiversity" specialists are counting in a certain area as many species as possible. The authors took part in such a day in the county of Forchheim (Upper Franconia, Northern Bavaria). In the vicinity of the little brook "Lillach" a variety of trees gave birth to the idea of fogging the canopy of different tree species to prove their uniqueness and attractiveness to specialized beetles and flies, or otherwise to see, if their canopy fauna is nearly all the same. As result 144 beetle species and 104 dipteran species could be cited. Among those occurring once only a few species can be taken as characteristic to their host tree. The faunistic composition depends more on the tree's neighbourhood than on its systematic status. Beech and spruce in a closed forest, oak and pine at the forest's rim, cherry as solitaire in a field nearby, and willow at a lane side offered no convincing canopy communities. But an oak and an ash with undergrowth showed impressive numbers in species and individuals. The beetles in particular were present with groups of species, which are absolutely specific for certain trees or structures, e.g. some Anobiidae and Scolytidae on coniferous wood. Decidous trees like oak and ash offered beetles characteristic for dead hardwood, while cherry and the mountain ash Sorbus torminalis attracted a lot of beetles known to be connected with woody Rosaceae. Among beetles several red data species could be found, headed by the very rare Sphaeriestes aeratus (Muss., 1859), Salpingidae. Within flies Spania nigra MG., 1830, Rhagionidae, is new to Bavaria