Studies on the aggregation pheromone of Ips subelongatus. II. The relationship between aggregation behaviour and its host plant tree.
Healthy bark of Larix dahurica [L. gmelinii] was found to be attractive to both male and female adults of the scolytid Ips subelongatus. Females were more attracted to host plant than non-host plant materials indicating that they locate the host tree by host plant odours. Compounds extracted by aeration from host tree bark, beetle frass and boring dust were highly attractive to females. Males were not attractive to females prior to feeding after emergence, but began to produce pheromone 4 hours after feeding had commenced. Pheromone activity peaked between 16 and 40 h later. The results indicate that feeding induces production of aggregation pheromone in I. subelongatus.