Evaluations of emamectin benzoate and propiconazole for protecting individual Pinus contorta from mortality attributed to colonization by Dendroctonus ponderosae and associated fungi
Article first published online: 19 AUG 2013
Published 2013. This article is a U.S. Government work and is in the public domain in the USA.
Pest Management Science
Volume 70, Issue 5, pages 771–778, May 2014
How to Cite
Fettig, C. J., Munson, A. S., Grosman, D. M. and Bush, P. B. (2014), Evaluations of emamectin benzoate and propiconazole for protecting individual Pinus contorta from mortality attributed to colonization by Dendroctonus ponderosae and associated fungi. Pest. Manag. Sci., 70: 771–778. doi: 10.1002/ps.3612
- Issue published online: 14 APR 2014
- Article first published online: 19 AUG 2013
- Accepted manuscript online: 18 JUL 2013 06:50PM EST
- Manuscript Accepted: 18 JUL 2013
- Manuscript Revised: 11 JUL 2013
- Manuscript Received: 16 MAY 2013
- lodgepole pine;
- mountain pine beetle;
- tree injections
Protection of conifers from bark beetle colonization typically involves applications of liquid formulations of contact insecticides to the tree bole. An evaluation was made of the efficacy of bole injections of emamectin benzoate alone and combined with the fungicide propiconazole for protecting individual lodgepole pine, Pinus contorta Dougl. ex Loud., from mortality attributed to colonization by mountain pine beetle, Dendroctonus ponderosae Hopkins, and progression of associated blue stain fungi.
Injections of emamectin benzoate applied in mid-June did not provide adequate levels of tree protection; however, injections of emamectin benzoate + propiconazole applied at the same time were effective for two field seasons. Injections of emamectin benzoate and emamectin benzoate + propiconazole in mid-September provided tree protection the following field season, but unfortunately efficacy could not be determined during a second field season owing to insufficient levels of tree mortality observed in the untreated control, indicative of low D. ponderosae populations.
Previous evaluations of emamectin benzoate for protecting P. contorta from mortality attributed to D. ponderosae have failed to demonstrate efficacy, which was later attributed to inadequate distribution of emamectin benzoate following injections applied several weeks before D. ponderosae colonization. The present data indicate that injections of emamectin benzoate applied in late summer or early fall will provide adequate levels of tree protection the following summer, and that, when emamectin benzoate is combined with propiconazole, tree protection is afforded the year that injections are implemented. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.