Forest Pests and Diseases near Lewistown, MT Amy Eckert Forest Pathologist

Insects 1.Mountain pine beetle : PP, LPP, and WP 2.Red turpentine beetle: PP,LP, and piñon 3.Douglas-fir bark beetle: Douglas-fir 4.Pine engraver beetle (Ips): pines 5.Western spruce budworm: Douglas-fir 6.Bronze birch borer: birch

Mountain pine beetle : PP, LPP, and WP Bluestain fungal spores

Mountain pine beetle : PP, LPP, and WP Look for small pitch tubes in bark and woodpecker feeding

Red turpentine beetle: PP,LP, and piñon Large pitch tubes: Combination of resin, bark dust, and frass

Douglas-fir bark beetle: Douglas-fir Look for insect frass or boring dust in bark crevices

Best beetle proofing strategy: Recognize high hazard situations and act to reduce potential beetle infestations What forest/tree conditions are most favored by beetles? What forest/tree conditions are most favored by good grass growth and grazing? Why can’t we just spray?

Target stand = sq. ft basal area 10”tree= tpa (16’x16’ = 170 tpa) 12”tree= tpa (18’X20’ = 121 tpa)

Infects slash and small pine trees. Pine engraver beetle (Ips): pines Look for tiny holes in bark and red boring dust on slash Best ips prevention?

Western spruce budworm: D-F, spruce and WL Adult Larvae Eggs Web-like material on branch ends, needles turn brown

Best spruce budworm prevention strategy: Enhance budworm predator habitat (birds, carpenter ants) how? Maintain tree health and vigor- how? why? Maintain adequate spacing and reduce thick understory regeneration Plant resistant trees such as pine and larch

Bronze birch borer: birch Top kill, branches die from the top down Keep birch healthy and vigorous: use iron enriched fertilizer, water. Prune infected branches.

Diseases 1.Aspen cankers and decline 2.White pine blister rust: WP 3.Western gall rust: LP and PP 4.Fire blight: apple species

Aspen Trees Cytospora canker of aspen Weak pathogen

Aspen Trees Cytospora canker on aspen stem with insect frass. Some insects that are attracted to aspen are: poplar borer, bronze poplar borer, bark beetles, ambrosia beetle. Insect Frass Weak insects

White pine blister rust Native or exotic? Ribes

Cotoneaster hedge with fire blight infection Peeling bark Canker-like twig discoloration General scorched- like appearance of infected twigs and leaves

Fire Blight

Western Gall Rust: Lodgepole and Ponderosa Infects young shoots and forms galls on branches, cankers and stems Remove infected trees during thinning. Increase air flow in stand