What's eating my rocky mountain bristlecone pine?

Rocky Mountain Bristlecone Pine shares pest pressures with its relatives: mountain pine beetle is the most serious threat, while pine aphids, needle scale, and tip-feeding moths can weaken younger trees. Porcupines strip bark in winter. This pine's dense resin gives it natural resistance, but drought-stressed trees are far more vulnerable.

Pitch tubes on bark; blue-stained wood; needles fade to red-brown as the tree dies Preventive permethrin bark sprays before adult flight; remove infested trees; maintain tree vigor with adequate water during drought

Dead shoot tips ('shepherd's crook'); resin-coated tunnels inside new growth; distorted branching on young trees Prune and destroy affected tips before adults emerge; spinosad or permethrin at bud-swell stage on young trees

Grey-white encrustations on needles; premature needle drop; overall thinning of canopy Horticultural oil in late spring targeting the crawlers; follow up with a second application 2–3 weeks later

Bark gnawed from lower trunk in winter; girdling can kill young trees Hardware cloth or metal trunk guards extending 60 cm above typical snowpack level