ATTRACTANT ISOLATED FROM FEMALE JEFFREY PINE BEETLES, DENDROCTONUS-JEFFREYI

The aggregation pheromone of Dendroctonus jeffreyi was investigated by combined gas chromatography and mass spectrometry of volatiles from hindguts of attacking beetles. The major compounds in females were identified as 1-heptanol and 2-heptanol, which are produced by oxidation of heptane present in the host resin. In field tests, 1-heptanol in combination with heptane was attractive, but racemic 2-heptanol was not. The addition of 2-heptanol to 1-heptanol appeared to reduce the number of beetles responding. The results indicate a probable difference between the chemical communication systems of D. jeffreyi and D. ponderosae, both of which have apparently adapted to utilize the metabolic products of potentially toxic hydrocarbons in their hosts. © 1979 Entomological Society of America.