Involvement of Methoprene-tolerant and Kruppel homolog 1 in juvenile hormone-mediated vitellogenesis of female Liposcelis entomophila (end.) (Psocoptera: Liposcelididae)

Methoprene-tolerant (Met) as an intracellular receptor of juvenile hormone (JH) and the Kruppel-homolog 1 (Kr-h1) as a JH-inducible transcription factor had been proved to contribute to insect reproduction. Their functions vary in different insect orders, however, they are not clear in Psocoptera. In this study, LeMet and LeKr-h1 were identified and their roles in vitellogenesis and ovarian development were investigated in Liposcelis entomophila (Enderlein). Treatment with exogenous JH III significantly induced the expression of LeKr-h1, LeVg, and LeVgR. Furthermore, silencing LeMet and LeKr-h1 remarkably reduced the transcription of LeVg and LeVgR, disrupted the production of Vg in fat body and the uptake of Vg by oocytes, and ultimately led to a decline in fecundity. The results indicated that the JH signaling pathway was essential to the reproductive process of this species. Interestingly, knockdown of LeMet or LeKr-h1 also resulted in fluctuations in the expression of FoxO, indicating the complex regulatory interactions between different hormone factors. Besides, knockdown of both LeMet and LeKr-h1 significantly increased L. entomophila mortality. Our study provides initial insight into the roles of JH signaling in the female reproduction of psocids and provided evidence that RNAi-mediated knockdown of Met or Kr-h1 is a potential pest control strategy.

Automated summary

In this study, the roles of Methoprene-tolerant (Met) and Kruppel-homolog 1 (Kr-h1) in the reproduction of Liposcelis entomophila were investigated. Knockdown of Met and Kr-h1 resulted in decreased vitellogenesis and ovarian development, leading to a decline in fecundity. Moreover, the expression of other hormone factors, such as FoxO, was also affected. These findings highlight the importance of JH signaling in female reproduction of psocids and suggest that RNAi-mediated knockdown of Met or Kr-h1 could be a potential pest control strategy.