Each species within the order Thysanoptera has a distinct mitochondrial gene order displaying a high level of gene rearrangement, particularly massive in Phlaeothripidae. To understand the evolutionary patterns of rearrangement in this family, we sequenced the complete mitochondrial genome of Psephenothrips eriobotryae, a notable potential pest of loquat trees. Its mitogenome is a circular DNA molecule (15,413 bp in size) composed of 37 genes: 13 PCGs, 22 tRNAs, two rRNAs, and two putative control regions (CRs). By comparing with the ancestral mitogenome of arthropods, P. eriobotryae exhibits notable gene rearrangement variations. However, it shares four conserved gene blocks with three closely related species in Phlaeothripinae. In the phylogenetic tree, P. eriobotryae was clustered with these three leaf-feeding Phlaeothripinae species. The presence of more similar conserved gene blocks probably indicates a strong correlation between gene rearrangements and the phylogeny within Phlaeothripidae. Furthermore, the mitogenome of P. eriobotryae shows some characteristics: (a) two putative CRs in which CR2 is the copy of partial CR1 with 99.62% sequence similarity, and CR1 consists of two 237 bp repeat unites; (b) high A+T content of 82.6% in overall base composition; (c) trnS1 lacking a complete dihydrouridine (DHU) arm; (d) the protein coding gene, atp8 started with TTG instead of the more common ATN, while nad3 terminated by TAG rather than TAA; (e) translocations and inversions observed in fifteen of the 37 genes.

Species are not only the fundamental units of taxonomy but also the basic units of pest management. Insects of Conogethes are important agricultural and forestry pests. However, species boundaries within Conogethes often appear obscure. In the present study, we re-evaluated the species status of Conogethes by applying three species delimitation approaches based on the mitochondrial DNA sequences, with particular emphasis on the yellow peach moth C. punctiferalis (Guenée, 1854). We first optimized species delimitation and inter-species genetic divergence threshold using a DNA barcoding dataset. The results revealed that several nominal species of Conogethes species harbored deeply diverged mitochondrial lineages which were recognized as independent species by the species delimitation methods. The p-distance between the delimited putative species ranged from 0.0159 to 0.1321 with a mean of 0.0841. Then we refined the species status of C. punctiferalis using the smallest interspecific distance threshold based on a geographically comprehensive population-scale dataset. This procedure narrowed the species concept of C. punctiferalis to a genetically coherent unit. Further investigation of its intraspecific divergence in the geographic context revealed that the refined C. punctiferalis was still widely distributed with the same or highly similar mitochondrial haplotypes occurring across South and East Asia.

The genus Diomus Mulsant, 1850 (Coleoptera: Coccinellidae: Diomini) from China is herein revised. Five species of Diomus are occurring in the Chinese fauna to date, including a new species from the Dafushan Mountains Forest Park, Guangzhou, Guangdong, namely D. dafushanensis Bi, Peng & Chen, sp. nov. Nomenclatural history, diagnosis, illustrations and distribution were provided for each species. A key to the native species of Diomus from China is also presented.