NEMATODE PARASITISM IN A DANISH DROSOPHILID COMMUNITY - FURTHER EVALUATION OF THE DISPROPORTIONATE PARASITISM HYPOTHESIS

The nematodes Parasitylenchus diplogenus and Howardula aoronymphium (A llantonematidae) are parasites of drosophilids (Diptera). Nematodes we re found in 3/14 drosophilid species sampled in Danish woodlands: Dros ophila phalerata Meigen (3.5% parasitism) was parasitized by H. aorony mphium and D. obscura Fallen (0.5%) and D. subobscura Collin (2.1%) by P. diplogenus. Parasitism was generally rare, and few drosophilid spe cies parasitized, compared to elsewhere in Europe. Parasitism was posi tively correlated with relative host abundance both within Denmark and across communities, suggesting that species diversity is promoted by a disproportionately high parasitism of more common host species. The prevalence of H. aoronymphium, but not P. diplogenus, parasitism is po sitively related to temperature across communities.