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BACKGROUND: Insulin signalling pathways play crucial roles in regulating growth and development in insects, but their effects on the growth and development of Arachnids, such as spiders, have rarely been studied. As a valuable pest natural enemy in agricultural fields, the molecular mechanisms of insulin signalling pathway‐mediated growth and development of the wolf spider, Pardosa pseudoannulata, are of particular interest. RESULTS: In this study, we identified and characterized six insulin signalling pathway genes – InR, InR2, IRS1, PI3K1, PI3K2, and PDK – in Pardosa pseudoannulata. Real‐time quantitative polymerase chain reaction results were used to analyse the relative expression levels of the six genes in different developmental instars and tissues, and in response to starvation treatment. In addition, the function of the insulin receptor substrate (IRS1) gene was investigated using RNA interference technology, which found that IRS1 significantly influenced nutrient content, developmental duration, body weight, and gonad development. CONCLUSION: This study revealed the roles of six key insulin signalling pathway genes in Pardosa pseudoannulata, and in particular the importance of the IRS1 gene in regulating growth and development in the spider. The results lay the foundation for further research on the internal regulation mechanisms of growth and development in Araneae species, and also provide a reference for the artificial breeding of spiders. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The Asian citrus psyllid (ACP) Diaphorina citri Kuwayama is the leading vector of Candidatus Liberibacter asiaticus ( C Las), the causative agent of citrus Huanglongbing (HLB) disease. The distribution and dynamics of C Las within ACP are critical to understanding how the transmission, spread and infection of C Las occurs within its host vector in nature. In this study, the distribution and titer changes of C Las in various tissues of ACP 5 th instar nymphs and adults were examined by fluorescence in situ hybridization (FISH) and real-time quantitative PCR (qPCR) techniques. Results demonstrated that 100% of ACP 5 th instar nymphs and adults were infected with C Las following feeding on infected plants, and that C Las had widespread distribution in most of the tissues of ACP. The titers of C Las within the midgut, salivary glands and hemolymph tissues were the highest in both 5 th instar nymphs and adults. When compared with adults, the titers of C Las in these three tissues of 5 th instar nymphs were significantly higher, while in the mycetome, ovary and testes they were significantly lower than those of adults. FISH visualization further confirmed these findings. Dynamic analysis of C Las demonstrated that it was present across all the developmental ages of ACP adults. There was a discernible upward trend in the presence of C Las with advancing age in most tissues of ACP adults, including the midgut, hemolymph, salivary glands, foot, head, cuticula and muscle. Our findings have significant implications for the comprehensive understanding of the transmission, dissemination and infestation of C Las, which is of much importance for developing novel strategies to halt the spread of C Las, and therefore contribute to the efficient prevention and control of HLB., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Guo, Kong, Mukangango, Hu, Liu, Sang and Qiu.)