Background: Light stimulation at a specific wavelength triggers various responses in insects and can be used for pest control. To develop efficient and ecofriendly photophysical pest control methods, the effects of green light on locomotion, growth (molting and eclosion) and reproduction in Nilaparvata lugens (Stål) (BPH), a major rice pest, were studied. Transcriptomics and transmission electron microscopy (TEM) were used to investigate the mechanisms involved.
Results: BPH adults showed disrupted daily locomotion patterns following green light treatment at night and exhibited abnormal locomotion peaks. Total 6-day locomotion of brachypterous adults was significantly greater than in the control group. The durations of growth stages 1-4 were all shorter under green light treatment than in the control, whereas the time from fourth molting to eclosion (stage 5) was significantly longer. When BPH adults under green light treatment began laying eggs, the egg hatching ratio (36.69%) was significantly lower than in the control (47.49%). Moreover, in contrast to the control, BPH molting and eclosion events tended to happen more at night. Transcriptome analysis proved that green light significantly affected the expression of genes involved in cuticular proteins, chitin deacetylase and chitinase, which are related to cuticular development. TEM observations confirmed abnormal cuticular development in nymph and adult BPHs (endocuticle, exocuticle and pore canals) under green light treatment.
Conclusion: Green light treatment at night notably affected locomotion, growth and reproduction in BPH, thus providing a novel idea for controlling this pest. © 2023 Society of Chemical Industry.
Keywords: circadian clock; cuticular development; eclosion; molting; pore canals; rice pest.
© 2023 Society of Chemical Industry.