Molecular analysis of the biting midges (Diptera: Ceratopogonidae), based on mitochondrial cytochrome oxidase subunit 2

Sequences from the mitochondrial cytochrome oxidase subunit 2 gene (cox2) were determined for 14 species from the family Ceratopogonidae, representing 12 genera and all five subfamilies, along with six representatives of other nematoceran families. The purpose was to develop a molecular phylogeny of the Ceratopogonidae, and interpret the phylogenetic position of the family within the infraorder Culicomorpha. These taxa have been analysed using cladistic methodology which, in combination with an excellent fossil record, provides a well established morphological phylogeny. Sequence analysis of cox2 revealed a high degree of sequence divergence among the species, reflecting in part the antiquity of the family, but also a significant acceleration of sequence evolution in the ceratopogonids compared to other nematoceran Diptera. Phylogenetic reconstruction by neighbor-joining and maximum parsimony gave strong support for an early separation of an ancient lineage that includes the two genera, Austroconops and Leptoconops, from the remainder of the family. The results support the existence of a clade that includes two subfamilies, Dasyheleinae and Forcipomyiinae, and this clade appears as sister to the remaining subfamily, Ceratopogoninae. The molecular phylogeny also supports monophyly of the Ceratopogonidae, and either a sister or paraphyletic relationship of this family with the Chironomidae.