Caterpillar-Induced Rice Volatile (E)-ß-Farnesene Impairs the Development and Survival of Chilo suppressalis Larvae by Disrupting Insect Hormone Balance

In this study, an artificial feeding study containing (E)-ß-farnesene (0.8g/kg) with C. suppressalis larvae was conducted to investigate its physical performance, and results revealed that the average 2nd instar duration in C. suppressalis significantly increased from 4.78 days to 6.31 days after Eßf treatment (P<0.001), and in 3rd instar C. larvae also significantly increased from 5.70 days to 8.00 days (P<0.001). There were no significant differences in 4th and 5th C. suppressalis larval between Eßf treatment and control(P>0.05). The mortality rates of 2nd C. suppressalis larvae were increased by 21.00-fold, compared with control(P<0.001), 3rd C. suppressalis larval increased by 6.39-fold(P<0.001). Comparative transcriptome analysis also showed that multiple DEGs involved in insect hormone biosynthesis pathway, the results of hormone assay in 3rd instar larvae showed the balance between juvenile hormones and ecdysteroids was disrupted. Eßf treatment increased juvenile hormones titers, but not the ecdysteroids. The results of qPCR were consistent with RNA-seq. Taken together, Eßf impairs the development and survival of C. suppressalis larvae by disrupting insect hormone balance. Moreover, the altered pathways were associated with carbohydrates, xenobiotics and cofactors and vitamins in C. suppressalis larvae. Altogether, our findings identify Eßf impair the development and survival of C. suppressalis larvae. Additionally, our data also revealed a potential mechanism that Eßf impaired the development and survival of C. suppressalis larval by disrupting insect hormone balance. These findings may contribute to the integrated control of C. suppressalis. Overall design: Examination of 2 different transcriptome in Chilo suppressalis.