Phylogenetic Analysis of the Family Lepidostomatidae (Trichoptera: Integripalpia) Using Whole Mitochondrial Genomes

Lepidostomatidae is a relatively large family of the infraorder Plenitentoria (Integripalpia), comprising four fossil genera and seven extant genera. Lepidostomatid adults exhibit pronounced sexual dimorphism and have thus been referred to as the 'cabinet of curiosities' within Trichoptera. However, only five annotated mitogenomes of <i>Lepidostoma</i> have been recorded in the GeneBank database, and some of these mitogenomes are incomplete. To better understand the structure of mitogenome and phylogenetic relationships of Lepidostomatidae, we present mitogenomes of 13 <i>Lepidostoma</i> species and one <i>Paraphlegopteryx</i> species for the first time. We combined these new mitogenomes with previously published data for a comparative analysis. The results showed that the structure of mitogenome was relatively conserved, the nucleotide composition was significantly AT biased, and the control region showed the highest A + T content. Evolutionary rate analysis showed that all protein-coding genes underwent purification selection. The phylogenetic relationships supported the monophyly of Lepidostomatidae and restored the taxonomic positions of the two subfamilies. Meanwhile, two monophyletic branches (<i>Lepidostoma ferox</i> branch and <i>Lepidostoma hirtum</i> branch) within the genus <i>Lepidostoma</i> were also strongly supported. These findings significantly advance our understanding of the mitogenome and phylogeny of Lepidostomatidae.