Chemosensory proteins (CSPs) were necessary for insect sensory system to perform important processes such as feeding, mating, spawning, and avoiding natural enemies. However, their functions in non-olfactory organs have been poorly studied. To clarify the function of CSPs in the development of Mythimna separata (Walker) larvae, two CSP genes, MsCSP17 and MsCSP18, were identified from larval integument transcriptome dataset. Both of MsCSP17 and MsCSP18 contained four conserved cysteine sites (C × (6)-C × (18)-C × (2)-C), with a signal peptide at the N-terminal. RT-qPCR analysis showed that MsCSP17 and MsCSP18 have different expression patterns among different developmental stages and tissues. MsCSP17 was highly expressed in 1st–4th instar larvae, and MsCSP18 had high expression in adults. Both genes were expressed highly in larval head, thorax, integument and mandible. Moreover, both of MsCSP17 and MsCSP18 were lowly expressed in larval integuments when larvae molted for 6 h and 9 h from 3rd to 4th instar, but highly at the beginning and end phase during molting. After injection of dsMsCSP17 and dsMsCSP18, the expression levels of two genes decreased significantly, with the body weight of larvae decreased, the mortality increased, and the eclosion rate decreased. It was suggested that MsCSP17 and MsCSP18 contributed to the development of M. separata larvae.

化学感应蛋白（CSP）是昆虫感觉系统执行重要过程（如取食、交配、产卵和躲避天敌）所必需的。然而，它们在非嗅觉器官中的功能却很少被研究。为了阐明 CSP 在粘虫(Walker) 幼虫发育中的功能，从幼虫珠被转录组数据集中鉴定了两个 CSP 基因MsCSP17和MsCSP18 。MsCSP17和MsCSP18均含有4个保守的半胱氨酸位点（C×（6）-C×（18）-C×（2）-C），N端有信号肽。RT-qPCR分析显示MsCSP17和MsCSP18在不同发育阶段和组织中具有不同的表达模式。MsCSP17在1~4龄幼虫中高表达，MsCSP18在成虫中高表达。这两个基因在幼虫头部、胸部、体被和下颌骨中高表达。此外，MsCSP17和MsCSP18在幼虫3～4龄蜕皮6 h和9 h时幼虫珠被中表达量较低，而在蜕皮开始和末期表达量较高。注射dsMsCSP17和dsMsCSP18后，两个基因的表达量显着下降，幼虫体重下降，死亡率增加，羽化率下降。有人认为，MsCSP17和MsCSP18有助于M. separata幼虫的发育。