REGIONALLY-SPECIFIC BIOACTIVITY OF 2 NEW PHEROMONES FOR DENDROCTONUS-RUFIPENNIS (KIRBY) (COL, SCOLYTIDAE)

1-Methyl-2-cyclohexen-1-ol (MCOL) was shown for the first time to occu r in the frass produced by female spruce beetles, Dendroctonus rufipen nis (Kirby). MCOL and 4-methylene-6,6-dimethylbicyclo [3.1.1]hept-2-en e (verbenene) were evaluated in five geographic locations for attracti veness to spruce beetles. In trapping experiments (+/-)- or (+)-MCOL e nhanced attraction to a standard blend of alpha-pinene with frontalin in two Alaska locations. (+)-MCOL was attractive and (-)-MCOL inhibito ry in south-central British Columbia, and (+)-, (-)- and (+/-)-MCOL we re all weakly attractive in one of three experiments in southeastern B ritish Columbia and northern Alberta. Verbenene was attractive only in combination with the standard blend plus MCOL in Alaska. In compariso n with the standard bait, tree baits incorporating (+/-)- or (+)-MCOL caused higher numbers of trees to be attacked in the interior Alaska l ocations and (+)-MCOL had the same effect in south-central British Col umbia. Density of attack on attacked trees was unaffected. (+/-)- or ( +)-MCOL could improve the operational efficacy of tree baits in Alaska , and (+)-MCOL could be used in southcentral British Columbia. Our res ults indicate that for wide-ranging scolytid species, operational eval uation of new semiochemicals should be regionally specific.