Treatment of lodgepole pine bark with neem demonstrates lack of repellency or feeding deterrency to the mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Scolytidae)

Recent research indicates that development of coniferophagous bark beetles can be severely disrupted by systemic applications of extracts from seeds of the neem tree, Azadirachta indica A. Jussieu. However, the potential for neem to repel or deter feeding has not been determined. Surface treatment to the run-off point with a neem based insecticide (2,000 ppm azadirachtin in 10% emulsifiable concentrate in water) to the boles of attractant-baited lodgepole pines, Pinus contorta var. latifolia Engelmann, was ineffective at repelling or deterring attack by the mountain pine beetle, Dendroctonus ponderosae Hopkins. Therefore, the activity of neem against the mountain pine beetle is limited to that of a systemically-applied insect growth regulator