Tree and Shrub Pests

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

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 Order: AcariFamily: Tetranychidae Description Spruce spider mite, Oligonychus ununguis  The spruce spider mite is a native pest of spruce and juniper. Adults are ...

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

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

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

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

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