Tree and Shrub Pests
Insects

Western spruce budworm
Western spruce budworm, Choristoneura freemani
Order: LepidopteraFamily: Tortricidae
Description
The western spruce budworm is native to North America and can defoliate Douglas-fir, true fir, ...

Tent caterpillars
Tent caterpillars
Order: LepidopteraFamilies: Erebidae, Lasiocampidae
Description
Tent caterpillars, Malacosoma spp.
The forest tent caterpillar (Malacosoma disstria) is commonly found in urban ...

Spotted Lanternfly
Spotted Lanternfly, Lycorma delicatula
Order: HemipteraFamily: Fulgoridae
Description
Spotted lanternfly (SLF) is an invasive planthopper native to Asia. They have straw-like mouthparts for ...

Spider mites in shade trees
Spider mites in shade trees
Order: AcariFamily: Tetranychidae
Description
Spruce spider mite, Oligonychus ununguisÂ
The spruce spider mite is a native pest of spruce and juniper. Adults are ...

Red turpentine beetle
Red turpentine beetle, Dendroctonus valens
Order: ColeopteraFamily: Curculionidae
Description
The red turpentine beetle is a native insect distributed throughout much of North and Central ...

Oystershell scale
Oystershell scale, Lepidosaphes ulmi
Order: HempiteraFamily: Diaspididae
Description
Unlike most insects, adult oystershell scales do not have legs, eyes, or antennae. Their appearance ...

Locust borer
Locust borer, Megacyllene robiniae
Order: ColeopteraFamily: Cerambycidae
Description
Locust borer adults have brightly colored yellow markings and are about 19 mm (0.75 inch) long. The beetles ...

Lilac borer
Lilac borer, Podosesia syringae
Order: LepidopteraFamily: Sesiidae
Description
Unlike most moth species, lilac borer adults are most active during the day. They resemble paper wasps (Poilstes ...

Japanese beetle
Japanese Beetle, Popillia japonica
Order: ColeopteraFamily: Scarabidae
Description
Japanese beetles have been one of the key insect pests of both turfgrass and landscape plants in the eastern ...

Ips beetles
Ips beetles, Ips spp.
Order: ColeopteraFamily: Curculionidae
Description
There are 11 species of Ips spp. inhabiting Colorado: Ips hunter, Ips pilifrons, Ips pini, Ips knausi, Ips calligraphus, ...

Horntails
Horntails, Sirex spp.
Order: Hymenoptera
Family: Siricidae
Description
Generally, horntail wasps are moderately large at about 37.5 mm (1.5 inches) and have broad heads with small eyes. Adult ...

Gambel oak borer
Gambel oak borer, Agrilus quercicola
Order: ColeopteraFamily: Buprestidae
Description
The Gambel oak borer is a native species of wood boring beetle found in forest stands of Gambel oak ...

European elm scale
European elm scale,
Eriococcus spuria
Order: Hemiptera
Family: Eriococcidae
Description
All scale insects undergo incomplete metamorphosis and have three life stages: egg, nymph, adult. These ...

Eriophyid mites
Eriophyid mites
Order: Acari
Family: Eriophyidae
Description
Adults have cylindrical bodies that taper at both the head and rear. They are translucent white or yellow and have two pairs of legs ...

Emerald ash borer
Emerald ash borer, Agrillus planipennis
Order: ColeopteraFamily: Buprestidae
Description
Emerald ash borer, abbreviated EAB, is an invasive beetle that was first detected in Colorado in 2013. ...

Elm leaf beetle
Elm leaf beetle, Xanthogaleruca luteola
Order: ColeopteraFamily: Chrysomelidae
Description
Elm leaf beetle is a pest of elm trees and a household nuisance when adults seek shelter during winter ...

Douglas-fir tussock moth
Douglas-fir tussock moth, Orgyia pseudotsugata
Order: LepidopteraFamily: Erebidae
Description
Young larvae of the Douglas-fir tussock moth are black with long body hairs. Mature larvae are ...

Dendroctonus spp.
Dendroctonus spp.
Order: ColeopteraFamily: Curculionidae
Description
Two Dendroctonus spp. are of particular significance in Colorado, the mountain pine beetle (Dendroctonus ponderosae) and ...

Brownheaded ash sawfly
Brownheaded ash sawfly, Tomostethus multicinctus
Order: HymenopteraFamily: Tenthredinidae
Description
Adults of the brownheaded ash sawfly resemble small dark black wasps that do not sting. ...

Brown soft scale
Brown soft scale, Coccus hesperidum
Order: HemipteraFamily: Coccidae
Description
Brown soft scales are small flattened oval insects that are common pests of greenhouse and house plants, and is ...

Aphids on shade trees and ornamentals
Aphids on shade trees and ornamentals
Order: HemipteraFamily: Aphididae
Description
Aphids are an extremely common insect in landscapes and gardens, and are one of the most common insects found ...

Agrilus difficilis
Agrilus difficilis
Order: ColeopteraFamily: Buprestidae
Description
Agrilus difficilis, commonly referred to as the honeylocust borer or flatheaded locust borer, is a species of wood boring ...