The ovipositor comprises the external genitalia of female insects, which plays an important role in the mating and ovipositing process of insects. However, it remains rudimentary of regional gene expression and physiological function in the ovipositor during structural development. Here, we analysed the basic structure and characteristics of the ovipositor in the migratory locust Locusta migratoria. RNA‐seq analysis revealed the specialization of chitin metabolism, lipids synthesis and transport, tanning and cuticular protein genes in the ovipositor. Among them, two cuticle protein genes, LmCP8 and LmACP79, were identified, which are specifically expressed in the ovipositor. Functional analysis based on RNA interference showed that deficiency of LmCP8 affected the structural development of the ovipositor resulting in the retention of a large number of remaining unproduced oocysts in the ovary of the locusts. Our results provide a fundamental resource to investigate the structural development and physiological function of the ovipositor in L. migratoria.

Insect wing consists of a double layer of epidermal cells that produce and secrete the dorsal and ventral cuticular components. It is important for the stability of epidermal cells during wing development and morphogenesis, but its specific gene expression and physiological function during this process remain unclear. In our previous work, a wing cuticle protein gene LmACP19 was identified in Locusta migratoria based on transcriptomic data. Here, we report on its roles in wing development and morphogenesis. LmACP19 encodes a chitin-binding protein belonging to RR-2 subfamily of CPR family, which is highly homologous to CP19-like proteins in other insect species. RT-qPCR analysis revealed that LmACP19 is highly expressed in wing pads of fifth-instar nymphs, and its encoded protein is located in two layers of epidermal cells but not in the cuticle. Suppression of LmACP19 by RNA interference led to abnormal wing pad and wing morphogenesis with curved, unclosed, and wrinkled phenotypes during nymph-to-nymph and nymph-to-adult transition, respectively. Furthermore, deficiency of LmACP19 affected arrangement of epidermal cells, resulting in apoptosis. Our results indicate that LmACP19 is indispensable for wing development and normal morphological structure by maintaining the stability of epidermal cells during L. migratoria molting.