Diadegma semiclausum is an important parasitoid wasp and widely used in the biological control of the diamondback moth, Plutella xylostella, one of the most destructive pests of cruciferous plants. Insect olfactory system is critical in guiding behaviors including feeding, mating, and oviposition, in which odorant binding proteins (OBPs) and odorant receptors (ORs) are two key components. However, limited attention has been paid to D. semiclausum olfactory genes. In this study, a transcriptome sequencing was performed on the RNA samples extracted from D. semiclausum male and female adult antennae. A total of 17 putative OBP and 67 OR genes were annotated and further compared to OBPs and ORs from P. xylostella, and other hemipteran parasitoid species. The expression patterns of D. semiclausum OBPs between male and female antennae were examined using reverse transcription polymerase chain reaction (RT-PCR) and quantitative real-time PCR. Six OBPs (DsemOBP 6, 7, 8, 9, 10, and 14) demonstrated significantly higher expression levels in females than in males, which may assist in female D. semiclausum host-seeking and oviposition behaviors. This study advances our understanding of the olfactory system of D. semiclausum at the molecular level and paves the way for future functional studies aiming at increasing the efficacy to control P. xylostella by using D. semiclausum.

Diadegma semiclausum是一种重要的寄生蜂，广泛用于小菜蛾Plutella xylostella的生物防治，小菜蛾是十字花科植物中最具破坏性的害虫之一。昆虫嗅觉系统对于指导包括进食、交配和产卵在内的行为至关重要，其中气味结合蛋白 (OBP) 和气味受体 (OR) 是两个关键组成部分。然而，对D. semiclausum嗅觉基因的关注有限。在这项研究中，对从D. semiclausum雄性和雌性成虫触角中提取的 RNA 样本进行了转录组测序。总共注释了 17 个推定的 OBP 和 67 个 OR 基因，并进一步与来自P. xylostella的 OBP 和 OR 进行比较和其他半翅目寄生蜂物种。使用逆转录聚合酶链反应 (RT-PCR) 和定量实时 PCR 检测雄性和雌性触角之间D. semiclausum OBPs的表达模式。六种 OBP（DsemOBP 6、7、8、9、10 和 14）在雌性中的表达水平显着高于雄性，这可能有助于雌性D. semiclausum宿主寻找和产卵行为。本研究在分子水平上加深了我们对半截球藻嗅觉系统的理解，并为未来旨在提高使用半截球藻控制小菜蛾的功效的功能研究铺平了道路。