Common Insect Problems With Trees

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Spruce and Pine Tree

Mountain Pine Beetle (MPB)

Generally targets the ponderosa, Scotch, and limber pine, with the occassional spruce.

Spruce IPS Bark Beetle

Attacks blue spruce and other long needle pine

Douglas-fir Tussock Moth

Generally on spruce

Aphids

Aphids infest a large variety of trees

Cooley Spruce Gall

Spruce branch ends show galls

Cottonwood, Aspen, and Poplar

Cottonwood Leaf Beetle

Generally targets cottonwood, poplar, and aspen

Oystershell Scale

Generally targets cottonwoods, ash, aspen, and cotoneaster

Petiolegall Aphid

Generally targets cottonwoods and poplars. It looks like a marble-like growth on leaf stalks

Poplar Blackmine Beetle

Can be found on cottonwood leaves, appears as large black patches on the leaves

Aphids

Aphids infest a large variety of trees

Crabapple, Hawthorn, Apple

Pearslug

Generally found on hawthorn trees and cotoneaster bushes

Woolly Apple Aphids

Found on apple, crabapple, and mountain-ash

Aphids

Aphids infest a large variety of trees

Elm

Banded Elm Bark Beetle

Generally found on Siberian elms

Spiny Elm Caterpillar

Generally found on elms and hackberry. This caterpillar feeds on deciduous tree leaves.

Elm Leaf Beetle

Generally found on elms

Aphids

Aphids infest a large variety of trees

Ash

Lilac/Ash Borer

Generally targets ash trees

Oystershell Scale

Generally targets cottonwoods, ash, aspen, and cotoneaster

Aphids

Aphids infest a large variety of trees

Maple

Cottony Maple Scale

Generally found on honeylocust and silver maples

Aphids

Aphids infest a large variety of trees

Honeylocust

Cottony Maple Scale

Generally found on honeylocust and silver maples

Honeylocust Plant Bug

Generally found on honeylocust trees

Aphids

Aphids infest a large variety of trees

Different Shrubs

Oystershell Scale

Generally targets cottonwoods, ash, aspen, and cotoneaster

Leafcutter Bee

Generally found on roses and other plants with larger leaves

Black Vine Weevil

Generally found on lilacs

Aphids

Aphids infest a large variety of trees