Black fungus gnats play an important role as the decomposers in the forest ecosystem. Their larvae live on various organic matters, and the subfamily Sciarinae, in particular, have restricted habitats that feed on dead woods in the deep forest. We compared the biodiversity of family Sciaridae from two different habitats, the clear-cutting area (CA) and the pitch pine forest (PF) by the emergence traps (ET) and the pitfall traps (PT) from May to October, 2010. A total of 12 species were reliably identified to the species among 19 unique taxa belonging to 9 genera 4 subfamilies from 716 collected black fungus gnats. Taxonomic studies show that Corynoptera bicuspidata (Lengersdorf, 1926) (200 individuals, 27.9 % of total) and Cory. sinedens Hippa, Vilkamaa & Heller, 2010 (74 individuals, 10.3 % of total) dominate in the PF and the CA, respectively. Species richness and abundance of CA is lower than those of PF. Any species of subfamily Sciarinae were not collected in the CA. These findings indicate that the biodiversity of Sciaridae was influenced by forest management such as clear cutting, which leads to the changes of canopy cover, dead woods and leaf litter layer.

The synanthropic flies are regarded as the most important vectors of infectious diseases. Especially, feeding and reproductive habits make flies the important vectors of many pathogens such as malaria, yellow fever, dengue fever, typhoid fever, dysentery, and anthrax. Although most of lower flies (e.g. black-flies, mosquitos, sand-flies) transport diseases by bloodsucking, the mechanical dislodgment from exoskeleton is one of the important mechanisms of pathogens transmission for higher flies (Diptera: Brachycera) such as blow-flies, flesh-flies, and house-flies. According to recent phylogenetic studies, the Bibionomorpha is suggested as a sister taxon of the Brachycera as a monophyletic group “Neodiptera”. Coincidently, a part of black fungus gnats (Diptera: Bibionomorpha: Sciaridae) are known as the important vectors of fungal diseases on agricultural crops due to the spores carrying by there fore tibial structures. We propose that the correlation of spore carrying structures and habitats adaptation in the Sciaridae. The evolutionary pathway tests support that the fore tibia structures appeared first and followed by live plant habitats in the Sciaridae. Regarding analyses, we hypothesized that the evolutionary benefit of fungal carrying structures could be closely related with the larval habitats adaptation of Sciaridae. Interestingly, both adults of the synanthropic higher flies and the black fungus gnats are carrying various microorganisms by mechanical dislodgment from there tibial exoskeleton. The common habits of those flies could be providing clues about the evolution of the fly-microorganism interections.

The phylogeny of the subfamily Sciarinae is reconstructed by the result of maximum likelihood, maximum parsimony, and Bayesian inference of 4,809 bp from two mitochondrial (COI and 16S) and two nuclear (18S and 28S) genes. The current subfamily Sciarinae is polyphyletic, since the genera Chaetosciara, Mouffetina, Schwenckfeldina, and Scythropochroa are grouped separately as the sister clade of other subfamilies. The monophyly of the genera Chaetosciara, Sciara, Scythropochroa, and Trichosia s. str. is strongly supported; however, the genus Leptosciarella s. l. is polyphyletic due to the separation of subgenus Leptosciarella (Leptospina) as a sister taxa of remaining Sciarinae (Leptosciarella s. str., Sciara, and Trichosia s. str.). The classification of the Sciarinae is revised and discussed on the basis of molecular phylogenetic hypotheses.