Biology of insect populations and communities in an
old-growth forest polypore Amylocystis lapponica

Atte Komonen, University of Helsinki

The distribution of the Amylocystis lapponica bracket fungus (Fig.1) in Finland is restricted to the north-eastern distribution of old-growth forest remnants. In my study I want toaddress two questions: 1) What is the community and food web structure of insects inhabiting A. lapponica? 2) Does forest fragmentation affect this community?

Over 400 fruiting bodies of Amylocystis lapponica were collected in 1997 to make comparisons between old-growth forest remnants in central Finland, and more continuous old-growth forests in eastern Finland and Russia. So far a total of 37 beetle, 10 fly, 2 bug and 6 parasitoid wasp species have been reared from the A. lapponica basidiocarps. Over 80 % of all 1924 beetle individuals were larvae of Hallomenus sp. (Melandryidae). Most other beetle species were generalist occupants of all decaying material. Fungivorous flies (Mycetophilidae & Tipulidae) were mainly parasitized by the diaprid wasp Cinetus piceus. The community structure (Fig.1) is constant between study regions as well as within regions.

Fig.1. The insect community structure in Amylocystis lapponica. Fungivorous beetles and flies are dependent on fungi to complete their life-cycle. Secondary beetles consume spores or decaying material, or they are predators. Fungivorous flies are mainly parasitized by the diaprid wasp Cinetus piceus.