Taxonomy and phylogeny of Sciaridae (Diptera)

Pekka Vilkamaa

Studies include taxonomy and phylogeny of the dipteran family Sciaridae, and the phylogeny of Bibionomorpha. Sciaridae are inconspicuous and tiny insects that have never attracted much attention by entomologists. The species and biology of Sciaridae are poorly known. Larvae live mostly in soil and decaying plant litter. Most larvae are obviously decomposers. Adults fly in vegetation or run on soil or tree trunks and other surfaces. Their feeding habits are known only in some cases of flower-feeding. They never suck blood.

In respect of their taxonomy, Sciaridae is probably the least studied of the large Nematoceran families and which might include 20 000 undescribed species in addition to ca. 1700 described ones. Especially rich the family is in the Tropics but even in Finland there are tens of still undescribed species.

The approach of the study is world-wide, although emphasis is in the Oriental area which is proving to be taxonomically most diverse (e.g. the genera Prosciara, Dolichosciara, Lobosciara and Pnyxiopalpus). Important part of the studies is also the revision of some important Holarctic genera such as the speciose Corynoptera. The generic revisions are being made preferably in connection with cladistic analyses in order to make the existing classification within the family more based on phylogenetic relationships of the species and groups. In basic taxonomic studies, a great effort is being given to raise the descriptive level of Sciaridae, which is necessary as the species are often morphologically very similar to each other, and generally have proved difficult to identify by non-specialists. In almost completely unexploited field of sciarid phylogeny, an essential part of the work is finding and interpreting applicable morphological characters for analyses, although molecular characters may also have high potential in reconstruction of phylogenies in this family.