Journal of the Entomological Society of British Columbia
In three separate experiments, Douglas-fir beetles, Dendroctonus pseudotsugae Hopkins, preferred traps baited with either (S)-(-)- or racemic (R,S)-(±)-frontalin over those baited with the (R)-(+)-enantiomer. Spruce beetles, D. rufipennis (Kirby), appeared to be attracted equally to both the (S)-(-)- and (R)-(+)-enantiomers, but low catches and high variance made interpretation of the data tenuous. For both species racemic frontalin was as attractive as the preferred enantiomer alone. The bark beetle predator,Thanasimus undatulus (Say), was attracted preferentially to (S)-(-)-frontalin over (R)-(+)- or (R,S)-(±)-frontalin in a Douglas-fir stand, while both enantiomers were equally attractive in a spruce stand.
Lindgren, B.S. Attraction of Douglas-fir beetle, spruce beetle and a bark beetle predator (Coleoptera: Scolytidae and Cleridae) to enantiomers of frontalin. J. Entomol. Soc. Brit. Columbia. 1992, 89, 13-17