Five mitochondrial genomes of black fungus gnats (Sciaridae) and their phylogenetic implications.

Sciaridae is a family of great species diversity, distributed worldwide, that includes important agricultural pests of cultivated mushrooms and plants produced in greenhouses. Here we sequenced five nearly complete mitochondrial genomes representing three subfamilies of Sciaridae. The lengths of these mitogenomes range from 13,849 bp to 16,923 bp with 13 protein-coding genes (PCGs), 20-22 transfer RNA (tRNA) genes, two ribosomal RNA (rRNA) genes, and a control region (CR). Compared with other dipteran species, rearrangements in Sciaridae are more common. Inversion or transition is observed frequently of trnL2, and in the tRNA clusters trnI-trnQ-trnM, trnW-trnC-trnY, and trnA-trnR-trnN-trnS1-trnE-trnF. Phylogenetic relationships within the family were reconstructed based on these newly sequenced species, combined with the published mitogenomes of related families, and recovered the topology within Sciaroidea as Cecidomyiidae + (Sciaridae + Keroplatidae). Relationships recovered within Sciaridae were Sciarinae + ('Pseudolycoriella group' + Megalosphyinae).