6 - Biosynthesis of Pheromones and Endocrine Regulation of Pheromone Production in Coleoptera

Abstract

This chapter discusses the biosynthesis of pheromones and endocrine regulation of pheromone production in Coleoptera. Coleopterans are known to utilize several types of pheromone biosynthetic pathways. Many pheromones are obtained through simple modifications of dietary components, while others are synthesized de novo from simple biogenic precursors. Symbiotic microorganisms may be involved in the biosynthesis of some pheromones, but as yet the significance of this contribution is not well understood. Examination of the metabolites of coleopteran symbionts has revealed that, in some cases, the microorganisms produce the same compounds that are utilized as pheromones by their host. Such symbionts include bacteria isolated from the grass grub beetle, Costelytra zealandica, a Serratia species isolated from the bark beetle Phloeosinus armatus, and a Bacillus cereus strain isolated from I. paraconfusus. This is not surprising as microorganisms, exposed to many of the same compounds as their hosts, could by coincidence metabolize some of these compounds to the same end products. To assess the importance of the microbial contribution to overall pheromone production, some studies have attempted to ascertain the metabolic capability of insects made as devoid as possible of their natural endo- and exo-symbionts.