RT Journal Article SR Electronic T1 Monoterpenoid signals and their transcriptional responses to feeding and juvenile hormone regulations in bark beetle Ips hauseri Reitter JF The Journal of Experimental Biology JO J. Exp. Biol. FD The Company of Biologists Ltd SP jeb.238030 DO 10.1242/jeb.238030 A1 Fang, Jia Xing A1 Du, Hui Cong A1 Shi, Xia A1 Zhang, Su Fang A1 Liu, Fu A1 Zhang, Zhen A1 Zu, Peng Juan A1 Kong, Xiang Bo YR 2021 UL http://jeb.biologists.org/content/early/2021/03/31/jeb.238030.abstract AB Hauser's engraver beetle Ips hauseri Reitter is a serious pest in spruce forest ecosystems in Central Asia. Its monoterpenoid signal production, transcriptome responses, and potential regulatory mechanisms remain poorly understood. The quality and quantity of volatile metabolites in hindgut extracts of I. hauseri were found to differ between males and females and among three groups: beetles that are newly emerged, those with a topical application of juvenile hormone III (JHIII), and those that have been feeding for 24 h. Feeding males definitively dominate monoterpenoid signal production in I. hauseri, which uses (4S)-(–)-ipsenol and (S)-(–)-cis-verbenol to implement reproductive segregation from I. typographus and I. shangrila. Feeding stimulation can induce higher expression of most genes related to the biosynthesis of (4S)-(–)-ipsenol than JHIII induction, and it shows a male-specific mode in I. hauseri. JHIII can stimulate males to produce large amounts of (–)-verbenone and also upregulates a higher expression of several CYP6 genes in males than females. The expression of genes involved in the metabolism of JHIII in females and males were found to be upregulated. A species-specific aggregation pheromone system for I. hauseri, consisting of (4S)-(–)-ipsenol and S-(–)-cis-verbenol, can be used to monitor population dynamics or mass trap killing. Our results also enable a better understanding of the bottom-up role of feeding behaviors in mediating population reproduction/aggregation and interspecific interactions.