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The brown planthopper (BPH), Nilaparvata lugens Stål (Hemiptera: Delphacidae) is one of the most destructive rice pests in Asia. The microbial metabolite decoyinine (DCY) has been extracted from Streptomyces hygroscopicus. Recent studies have suggested that treating rice seeds with DCY could improve the growth and yield of rice. To further assess the effects of priming the seeds of different rice varieties with DCY on rice seedling resistance against BPH, an age-stage, two-sex life table and choice test were applied to investigate the individual fitness, population parameters, and preference behavior of BPHs in this study. The results indicated that feeding on rice seedlings grown from seeds primed with DCY significantly affected BPHs' adult longevity, oviposition period, fecundity, as well as the net reproductive rate (R0), intrinsic rate of increase (rm), finite rate of increase (λ), doubling time (DT), and population size in terms of BPH. The honeydew excretions and the weights of BPHs fed on DCY-pretreated rice plants were remarkably lowered. The two-way ANOVA results also showed that there were significant differences in the biological parameters, honeydew excretions, and of BPH weights owing to DCY treatment, rice variety, and the interactions between DCY treatment and rice variety. Additionally, the feeding and oviposition preferences of BPHs for the pretreated rice plants were reduced. Our results imply that the priming of seeds with DCY can improve rice resistance against BPH, which could facilitate the utilization of seed priming as a new avenue for effective crop protection. [ABSTRACT FROM AUTHOR]

The brown planthopper (BPH), Nilaparvata lugens , is a destructive pest of rice in Asia. The secondary metabolite, decoyinine (DCY), is produced by Streptomyces hygroscopicus. Previous studies on DCY have focused on its antimicrobial and antitumor properties. However, its effect on insect resistance of rice remains unclear. Here, we investigated whether pretreatment of rice seeds with DCY improves plant resistance against BPH. The results showed that rice plants grown from DCY-pretreated seed displayed higher resistance to BPH. Two sex life table analyses revealed that the fecundity, the intrinsic rate of natural increase (r m), the net reproductive rate (R 0), the finite capacity of increase (λ) and population size of BPH fed on rice pretreated with DCY significantly decreased compared to the control. The ovary development and the expression level of vitellogenin (NlVg) were decreased in BPH fed on DCY-pretreated rice. Seed priming with DCY significantly increased the duration and number of occurrence of the np, N2, N3 waveforms and decreased the duration of N4-b waveforms of BPH. Additionally, seed priming with DCY also decreased the feeding and oviposition preference of rice to BPH. Therefore, we inferred that seed priming with DCY could enhance rice resistance to BPH. [Display omitted] • Seed priming with decoyinine could enhance rice resistance to the brown planthopper. • The fecundity, ovary development and the expression level of NlVg were decreased. • The population size, feeding and preference of brown planthopper were affected. [ABSTRACT FROM AUTHOR]