# Presentation: 488901

## Forest Pests and Diseases near Lewistown, MT 

**Amy Eckert**
***Forest Pathologist***

## Insects

- Mountain pine beetle : *PP, LPP, *and* WP*
- Red turpentine beetle: PP,LP, and piñon
- Douglas-fir bark beetle: *Douglas-fir*
- Pine engraver beetle (Ips): *pines*
- Western spruce budworm: *Douglas-fir*
- Bronze birch borer: *birch*

## Mountain pine beetle : PP, LPP, and WP

**Mountain pine beetle : *****PP, LPP, *****and***** WP***

**Bluestain fungal spores**

## Mountain pine beetle : PP, LPP, and WP

**Mountain pine beetle : *****PP, LPP, *****and***** WP***

**Look for small pitch tubes in bark and woodpecker feeding**

## Red turpentine beetle: PP,LP, and piñon

**Red turpentine beetle: *****PP,LP*****, and *****pi******ñ******on***

- Large pitch tubes: Combination of resin, bark dust, and frass

## Douglas-fir bark beetle: Douglas-fir

**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?**

## Slide 8

## Slide 9

## Slide 10

## Target stand = 80-100 sq. ft basal area

**Target stand = 80-100 sq. ft basal area**
**10”tree= 150-180 tpa    (16’x16’ = 170 tpa)                                 **
**12”tree= 100-125 tpa    (18’X20’ = 121 tpa)**

## Infects slash and small pine trees.

**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

**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

**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

- Aspen cankers and decline
- White pine blister rust: *WP*
- Western gall rust: *LP* and *PP*
- Fire blight: *apple species*

## Aspen Trees

**Aspen Trees**

**Cytospora canker of aspen**

**Weak pathogen**

## Aspen Trees

**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

**White pine blister rust**
**Native or exotic?**

***Ribes***

## Cotoneaster hedge

**Cotoneaster hedge**
**with fire blight infection**

- Peeling bark

- Canker-like twig discoloration

**General scorched-like appearance of infected twigs and leaves**

## Fire Blight

**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**