RNA interference in Pardosa pseudoannulata, an important predatory enemy against several insect pests, through ingestion of dsRNA‐expressing Escherichia coli

Abstract

RNA interference is an important technology for gene functional research in many organisms. The pond wolf spider (Pardosa pseudoannulata) is an important natural enemy of rice field pests. To facilitate large‐scale gene functional research in this spider species and others, we developed an RNA interference (RNAi) method via ingestion of bacteria expressing dsRNA. The dsRNA targeting a cytochrome P450 monooxygenase (cyp41g2) was expressed in Escherichia coli HT115 (DE3). And then the bacterial suspension was fed to 14–20 days old spiderlings. The mRNA abundance of the target gene was significantly reduced after 3‐day's ingestion of bacteria expressing dsRNA, and between day 5 and 7, RNAi efficiency remained stable. Thus, we selected 5 days as the optimum interference time. Furthermore, the bacteria resuspension containing 20 ng/μl dsRNA was selected as the optimum concentration. To evaluate the applicability of this method, three other genes with different tissue expression pattern were also selected as targets. And the mRNA abundance of all the four target genes was significantly reduced with RNAi efficiency between 66.0% and up to 86.9%. The results demonstrated that the oral delivery of bacteria expressing dsRNA would be an effective RNAi method for the gene functional study in P. pseudoannulata.

The effects of prey lipid on female mating and reproduction of a wolf spider

“…The wolf spider Pardosa pseudoannulata (Araneae: Lycosidae) is one of the most important predators against diverse pests found in rice paddies in China ( Lou et al 2014 ; Xiao et al 2016 ; Guo et al 2018 ; Hou et al 2021 ), and there are 2–3 generations a year ( Zhao 1993 ). In the present study, we aimed to investigate the effects of the lipid content extracted from fruit flies Drosophila melanogaster on female mating behavior, sexual cannibalism, and reproductive success in the wolf spider, P. pseudoannulata in the laboratory.…”