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 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.