Effect of trap height on capture of ceramycid beetles with fermenting baits

We tested the hypothesis that the altitude at which adult cerambycid beetles fly is associated with the feeding ecology of their larvae.  For example, we predict that adults of branch girdling species would be active high in the canopy, while species that colonize fallen branches would be most active near ground level.  We tested the hypothesis using flight-intercept traps positioned at three heights relative to the forest floor: standard trap height (1.5 m), near the middle of tree boles (6 m), and at mid canopy (12 m).  Traps were set up at two study sites that were dominated by oaks and hickories.  At each site, two sets of the tree trap height treatments were set up, one set with traps baited with a blend of pheromones of multiple cerambycid species, and the other set baited with a fermenting bait that simulated volatiles from wounded trees.  Numbers of beetles captured per trap was significantly influenced by the trap height treatment for four cerambycid species.  The only species that was attracted to the fermenting bait was Eburia quadrigeminata, consistent with its larvae requiring dead hosts, and most adults were captured in the tree canopy.  The remaining species were attracted only by the pheromone blend.  Both Astylidius parvus and Xylotrechus colonus were captured primarily by traps at ground level, while 83 % of adult Phymatodes lengi were captured in the tree canopy.  Our findings for P. lengi may provide important information for identifying the larval hosts, which at present are not known.