4 - Pheromone production in bark beetles

Abstract

This chapter presents our current knowledge of pheromone production in bark beetles, emphasizing the biochemical, molecular, functional genomics, and post-genomic studies in Ips and Dendroctonus species. Ipsdienol, ipsenol and cis-verbenol were identified as the first aggregation pheromone components from bark beetles in 1966. Since then, many additional components were identified as both aggregation and anti-aggregation pheromones, with several being monoterpenoids. We discuss the historical belief that monoterpenoid bark beetle pheromones were derived from host terpenes, and then the discovery that many are in fact biosynthesized de novo through the mevalonate pathway. We describe the known biosynthetic pathways for pheromones in Ips and Dendroctonus, both de novo and those derived from host monoterpenes, and their regulation. We then put pheromone biosynthesis and the detoxification of host compounds into an evolutionary context. Finally, we point out areas where research is needed to obtain a more complete understanding of pheromone production.