Jon Sweeney, Peter Silk, and Ed Kettela
Natural Resources Canada, Canadian Forest ServiceľAtlantic Forestry Centre,
SERG Project #2002/01
Year of Project: 2005
Report Received: 2006
Headspace samples showed that a small number of male T. cinnamopterum were emitting hydroxy hexanones or hexane-diols, similar in structure to the long range pheromones identified in other Cerambycids. Racemic 2,3 hexane diols, racemic 3-hydroxy-2-hexanone and R-3-hydroxy-2-octanone, were synthesized and shown to elicit strong antennal responses in both sexes of T. fuscum and T. cinnamopterum. In field trapping experiments, the racemic 3-hydroxy-2-hexanone and R-3-hydroxy-2-octanone were unattractive by themselves, but during the first two weeks of trapping, the combination of racemic 3-hydroxy-2-hexanone plus host volatiles trapped significantly more female T. fuscum than traps baited with host volatiles alone. Laboratory bioassays demonstrated that copulatory behavior in male T. fuscum and T. cinnamopterum was triggered by contact pheromones on the cuticle of conspecific females. Males were observed to display copulatory behavior immediately on contact with dead conspecific females, but did not respond to dead females that had been rinsed in hexane, indicating that copulation is triggered primarily by a chemical stimulus. Three candidate contact pheromones (present in female but much lower or absent in male hexane rinses) were identified and synthesized in each of T. fuscum and T. cinnamopterum, and are similar to those identified as contact pheromones in other cerambycids.