Chitin synthase (CHS) plays a key role in chitin synthesis. CHS1 is ubiquitous in insects, and some studies have found that the RNA interference with CHS1 can hinder three types of molting processes (larva–larva, larva–pupa and pupa–adult). In the present study, the CHS1 of Monochamus alternatus was identified and characterized by a bioinformatics analysis. The developmental stage-specific expression of the MalCHS1 (Monochamus alternatus CHS1) gene was obtained by a RT-qPCR, and the corresponding dsRNA was designed for functional verification. The RNA interference experiment was conducted using the microinjection method, and the injection site was selected from the abdominal segments of fifth-instar larvae. The results showed that after silencing the CHS1 gene, the larvae of M. alternatus showed morphological abnormalities, such as the softening of the body wall, a transparent abdomen and the swelling of somites, indicating that MalCHS1 mediates the molting, growth and development of M. alternatus. RNAi-mediated MalCHS1 gene silencing may become a promising new biological pesticide that can provide a new target gene for pest control.

In this study, Odontolabis taynguyensis Xin, Zhong & Qi, sp. nov., is described from central Vietnam based on morphological and mitochondrial COI gene evidence. The new species could be distinguished from related species by external characters. Phylogenetic analysis supports designating O. platynota coomani (Didier, 1927) as a junior synonym of O. p. platynota (Hope, 1845), as both genetic distance and tree topology demonstrate that O. p. coomani is nested within the O. p. platynota clade and lacks an independent lineage.

In this paper, we describe a new stag beetle species from Yunnan, China, i.e., Neolucanus horizontalis Xin, Zhong & Qi, new species which exhibits significant structural differences in mandible, labial vestiture, protibia and male genitalia compared to related species. We also provide redescription of the male of N. fuscus Didier, 1926 and N. brochieri Bomans & Miyashita, 1997. Neolucans fuscus zhongguo Schenk, 2012 is synonymized with N. fuscus fuscus Didier, 1926. We also present a distribution map and an identification key for the telodont males of the N. fuscus group. Finally, we discuss the species group affiliation of N. baongocae Nguyen, 2013.

In the present study, a new stag beetle, namely Prosopocoilus wangae Qi, Bian & Xin, sp. nov., from Vietnam is described and illustrated. This new species has long been misidentified as the Vietnamese population of P. mysticus mysticus Parry, 1870, but it can be clearly distinguished from the latter by its external details and genital characters. Moreover, an updated checklist of Vietnamese taxa of Prosopocoilus Hope, 1845 is provided.

The present study describes a new species from Guizhou, China, i.e., Falcicornis banjinshuaii Xin, Yang & Zhong, sp. nov., within the F. bisignatus group. The new species can be conspicuously distinguished from its related congeners based on morphological characters and the COI analyses. Additionally, a checklist of genus Falcicornis Planet, 1894 is provided.

Despite centuries of active research on Eurasian Lucanidae, the absence of species with vestigial hindwings has remained a significant knowledge gap. This study addresses this gap by establishing the new genus Geonigidius Xin, Gong, Zhong & Qi, gen. nov., with Geonigidius sinensis Xin, Gong, Zhong & Qi, sp. nov. from the southern Xizang Autonomous Region, China, as its type species. The species exhibits the key feature of vestigial hindwings, which has not been reported unreported in any Eurasian congeners. A checklist of tribe Figulini Burmeister, 1847 species from China and an identification key for Chinese genera of Figulini are provided.