Abstract: 【Aim】 To explore the structure characteristics of the mitochondrial genome of Stephanitis nashi and the phylogenetic relationships within Cimicomorpha at the family level. 【Methods】 The complete mitochondrial genome of S. nashi was sequenced by using high-throughput sequencing technology. The phylogenetic relationships within Cimicomorpha at the family level, with the mitochondrial genomes of 150 species known to Cimicomorpha as ingroups and those of two Pentatomomorpha species as outgroups, were reconstructed using maximum likelihood (ML) and Bayesian inference (BI) methods. 【Results】 The mitochondrial genome of S. nashi (GenBank accession no.: OP650254) is 15 045 bp in full-length, which contains 37 genes including 13 protein-coding genes (PCGs), 22 tRNA genes, two rRNA genes and a non-coding control region. Among the 13 PCGs, except that the start codon of nad5 is ATC, the start codons of the other PCGs are ATT, ATA or ATG. While cox2 and nad4l employ the incomplete T as the stop codon, the other 11 PCGs terminate with complete stop codons of TAA or TAG. All tRNA genes can be folded into typical cloverleaf structure. The lengths of the rRNA genes rrnL and rrnS are 1 237 and 763 bp, with the A+T content of 81.08% and 82.04%, respectively. Both ML and BI produced a similar phylogenetic relationships within Cimicomorpha: the families Tingidae, Cimicidae, Thaumastocoridae, Miridae, Plokiophilidae, Microphysidae, Velocipedidae, Anthocoridae, Nabidae, Pachynomidae and Phymatidae were monophyletic, respectively. However, the family Reduviidae was non-monophyletic. The Tingidae had close relationships to Thaumastocoridae and part of Reduviidae. 【Conclusion】 This study reconstructed the phylogenetic relationships within the Cimicomorpha based on the mitochondrial genome data, revealing the non-monophyly of the family Reduviidae and the monophyly of the other 11 families, and it will contribute to increasing our knowledge about the phylogeny and the mitogenomics of Cimicomorpha.

Key words:  Stephanitis nashi, Cimicomorpha, Tingidae, mitochondrial genome, phylogeny