Sublethal and transgenerational effects of a potential plant-derived insecticide, beta-asarone, on population fitness of brown planthopper, Nilaparvata lugens

Many essential oils have excellent insecticidal activity and have the potential to be developed as alternatives to chemical insecticides for pest control. Previously, we showed that beta-asarone, a major constituent of the essential oil derived from Acorus calamus L. (Acoraceae), has strong pesticidal activity against brown planthopper, Nilaparvata lugens (Stal) (Hemiptera: Delphacidae), the most notorious rice pest in Asia. Here, we report the first evaluation of the sublethal and transgenerational effects of beta-asarone on N. lugens. beta-Asarone significantly decreased female longevity, male longevity, fecundity, and hatchability of F-0 generation individuals exposed to the LD30 and LD45 of beta-asarone relative to the acetone control. Moreover, compared with acetone, exposure to LD30 and LD45 of beta-asarone significantly shortened the duration of the egg stage, developmental duration of first instars, and female longevity of F-1 generation individuals. Furthermore, the intrinsic rate of increase (r), finite rate of increase (lambda), and net reproductive rates (R-0) of insects treated with LD30 and LD45 of beta-asarone were significantly lower than those of insects treated with acetone. Compared with acetone, the fecundity and hatchability of F-1 generation individuals were significantly decreased after exposure to beta-asarone at LD30 and LD45. These findings indicate the negative effects of sublethal doses of beta-asarone on N. lugens and provide novel information on the potential use of beta-asarone as a substitute chemical pesticide.