Evaluation of Frontalin and Exo-brevicomin as Kairomones to Control Mountain Pine Beetle (Coleoptera: Scolytidae) in Lodgepole Pine

Abstract

Augmentation of entomophagous insects with synthetic attractants for control of mountain pine beetle, Dendroctonus ponderosae Hopkins, was evaluated in lodgepole pine, Pinus contorta var. latifolia Engelmann, stands located in central Idaho and north-eastern Oregon. The clerid predator, Thanasimus undatulus (Say), was the only species that responded to sticky traps baited with either frontalin or exo-brevicomin. Significantly more adults responded to frontalin, and exo-brevicomin was eliminated from subsequent tests. Frontalin was successful in augmenting T. undatulus adults on trees baited either before (May–mid-July) or during (mid-July–September) the mountain pine beetle flight period. Baiting before the bark beetle flight period was most effective in augmenting T. undatulus , because baiting was concurrent with peak flight activity of the clerid. Frontalin, in association with the host trees, also attracted mountain pine beetle when used during the latter's flight period. Augmentation of T. undatulus adults without aggregating mountain pine beetle was accomplished by removing the attractant before the flight period of the latter. Baiting brood trees in this manner increased the incidence of T. undatulus larvae 3-fold, and mortality of emerging mountain pine beetle adults by 7.1%, but did not significantly reduce pine beetle brood survival or consequent tree mortality. However, the influence of the substantially increased predator population may be synergistic with other control tactics, and the use of frontalin should be considered seriously within a pest management program.