Byers, J.A., Lanne, B.S., & Löfqvist, J. 1989c. Host-tree
unsuitability recognized by pine shoot beetles in
flight. Experientia 45:489-492.
In spring, the landing rate of flying European pine shoot beetles,
Tomicus piniperda L., on injured Scots pine diminishes as
colonization continues. This is due to olfactory cues that indicate
progressive host degradation. Verbenone was shown to play a role in
the beetle's recognition of this unsuitability of a formerly suitable
host, since the compound was increasingly released from colonized
tree sections as they aged, but not from uninfested sections. Also,
the release of verbenone at natural rates in the forest inhibited the
attraction of beetles to host monoterpenes.