PHEROMONES IN IPS (COLEOPTERA: SCOLYTIDAE): OCCURRENCE AND PRODUCTION

Abstract

AbstractComparative gas chromatographic analyses of volatiles generated by Ips indicate the presence of cis- and trans-verbenol in hindguts of the 12 species investigated. The biosynthesis of verbenol does not require feeding, but instead results from the insect’s contact with oleoresin. Ipsdienol is the most frequently occurring pheromone in Ips species after feeding. Aggregation of these bark beetles appears to be regulated by two distinct functional types of pheromones, i.e. contact pheromones, produced and/or released upon contact with new host material, and frass pheromones, which require actual feeding in the new host’s tissues. The aggregation of aggressive bark beetle species seems to be largely dependent on contact pheromones, whereas the host’s susceptibility to feeding is indicated by the release of frass pheromones.