Christmas Tree Growers

Christmas Tree Pests and Diseases

The information here focuses on newer pests -- including insects, mites and diseases -- for which management information has been difficult to find. It supplements existing resources like the USDA Forest Service's Christmas Tree Pest Manual.

Many of the recommendations here include use of pesticides. Although this information should be up to date, labels and product registrations do change frequently. If any of the information here conflicts with that on pesticide labels, you must follow the label.

Other helpful resources:

University of Wisconsin Plant Disease Diagnostics Clinic, Dr. Brian Hudelson, 608-262-2863

Wisconsin Pest Survey grower participation

Balsam Fir

Pest Name Scientific Name Resource Link(s)
Armillaria Root Rot Armillaria Armillaria Root Rot, and then scroll down the page to the specific pest of interest.
Balsam Fir Needle Rust Uredinopsis spp. Balsam Fir Needle Rust, and then scroll down the page to the specific pest of interest.
Balsam Gall Midge Paradiplosis tumifex

Balsam Gall Midge (USDA), and then scroll down the page to the specific pest of interest.

Balsam Gall Midge (Vermont)

Balsam Twig Aphid Mindarus abietinus

Balsam Twig Aphid (USDA), and then scroll down the page to the specific pest of interest.

Balsam Twig Aphid (Minnesota)

Balsam Twig Aphid (Massachusetts -Amherst), and then scroll down the page to the specific pest of interest.

Broom Rust of Fir Melampsorella caryophyllacearum Broom Rust of Fir, and then scroll down the page to the specific pest of interest.
Delphinella Shoot Blight Delphinella abietis

Delphinella Shoot Blight (Wisconsin DNR), and then scroll down the page to the specific pest of interest.

Delphinella Shoot Blight (Vermont), and then scroll down the page to the specific pest of interest.

Lirula Needlecast of Fir

Lirula nervata or

Lirula mirabilis
Lirula Needlecast of Fir, and then scroll down the page to the specific pest of interest.
Mound Ant   Mound Ant
Phomopsis Shoot Blight Phomopsis Abies Phomopsis Shoot Blight, and then scroll down the page to the specific pest of interest.
Phytophthora Root Rot Phytophthora spp. Phytophthora Root Rot
Rhizosphaera Needle Blight of Fir Rhizosphaera pini Rhizosphaera Needle Blight of Fir, and then scroll down the page to the specific pest of interest.
Spruce Spider Mites Oligonychus ununguis

Spruce Spider Mites (USDA), and then scroll down the page to the specific pest of interest.

Spruce Spider Mites (Minnesota)

White Grubs Phyllophaga White Grubs, and then scroll down the page to the specific pest of interest.

Blue Spruce

Pest Name Scientific Name Resource Link(s)
Armillaria Root Rot Armillaria Armillaria Root Rot, and then scroll down the page to the specific pest of interest.
Cooley Spruce Gall Adelgid Adelges cooleyi

Cooley Spruce Gall Adelgid (USDA), and then scroll down the page to the specific pest of interest.

Cooley Spruce Gall Adelgid (Minnesota)

Phytophthora Root Rot Phytophthora spp. Phytophthora Root Rot
Rhizosphaera Needlecast of Spruce Rhizosphaera kalkhoffii

Rhizosphaera Needlecast of Spruce (USDA), and then scroll down the page to the specific pest of interest.

Rhizosphaera Needlecast of Spruce (Minnesota)

Spruce Needleminers

Endothenia albolineana
or

Epinotia nanana
Spruce Needleminers, and then scroll down the page to the specific pest of interest.
Spruce Spider Mites Oligonychus ununguis

Spruce Spider Mites (USDA), and then scroll down the page to the specific pest of interest.

Spruce Spider Mites (Minnesota)

Stigmina Needlecast

Stigmina lautii

Stigmina Needlecast
Weir’s Cushion Rust Chrysomyxa weirii Weir’s Cushion Rust
White Grubs Phyllophaga White Grubs, and then scroll down the page to the specific pest of interest.
White Pine Weevil Pissodes strobi

White Pine Weevil (USDA), and then scroll down the page to the specific pest of interest.

White Pine Weevil (Minnesota)

Concolor Fir

Pest Name Scientific Name Resource Link(s)
Armillaria Root Rot Armillaria Armillaria Root Rot, and then scroll down the page to the specific pest of interest.
Delphinella Shoot Blight Delphinella abietis

Delphinella Shoot Blight (Wisconsin DNR), and then scroll down the page to the specific pest of interest.

Delphinella Shoot Blight (Vermont), and then scroll down the page to the specific pest of interest.

Phytophthora Root Rot Phytophthora spp. Phytophthora Root Rot
White Grubs Phyllophaga White Grubs, and then scroll down the page to the specific pest of interest.

Douglas Fir

Pest Name Scientific Name Resource Link(s)
Armillaria Root Rot Armillaria Armillaria Root Rot, and then scroll down the page to the specific pest of interest.
Phytophthora Root Rot Phytophthora spp. Phytophthora Root Rot
Rhabdocline Needlecast Rhabdocline pseudotsugae Rhabdocline Needlecast, and then scroll down the page to the specific pest of interest.
Swiss Needlecast Phaeocryptopus gäumanni Swiss Needlecast, and then scroll down the page to the specific pest of interest.
White Grubs Phyllophaga White Grubs, and then scroll down the page to the specific pest of interest.

Fraser Fir

Pest Name Scientific Name Resource Link(s)
Armillaria Root Rot Armillaria Armillaria Root Rot, and then scroll down the page to the specific pest of interest.
Balsam Gall Midge Paradiplosis tumifex

Balsam Gall Midge (USDA), and then scroll down the page to the specific pest of interest.

Balsam Gall Midge (Vermont)

Balsam Twig Aphid Mindarus abietinus

Balsam Twig Aphid (USDA), and then scroll down the page to the specific pest of interest.

Balsam Twig Aphid (Minnesota)

Balsam Twig Aphid (Massachusetts-Amherst), and then scroll down the page to the specific pest of interest.

Broom Rust of Fir Melampsorella caryophyllacearum Broom Rust of Fir, and then scroll down the page to the specific pest of interest.
Conifer Root Aphid Prociphilus americanus Conifer Root Aphid
Phytophthora Root Rot Phytophthora spp.

Phytophthora Root Rot

Rhizosphaera Needle Blight of Fir

Rhizosphaera pini

Rhizosphaera Needle Blight of Fir, and then scroll down the page to the specific pest of interest.
Spruce Spider Mite Oligonychus ununguis

Spruce Spider Mites (USDA), and then scroll down the page to the specific pest of interest.

Spruce Spider Mites (Minnesota)

White Grubs Phyllophaga White Grubs, and then scroll down the page to the specific pest of interest.

Scotch Pine

Pest Name Scientific Name Resource Link(s)
Armillaria Root Rot Armillaria Armillaria Root Rot, and then scroll down the page to the specific pest of interest.
Brown Spot Needle Blight Mycosphaerella dearnessii Brown Spot Needle Blight, and then scroll down the page to the specific pest of interest.
Cyclaneusma Needlecast Cyclaneusma minus Cyclaneusma Needlecast, and then scroll down the page to the specific pest of interest.
Eastern Pine Gall Rust Cronartium quercuum Eastern Gall Rust, and then scroll down the page to the specific pest of interest.
European Pine Shoot Moth Rhyacionia buoliana

European Pine Shoot Moth (USDA), and then scroll down the page to the specific pest of interest.

European Pine Shoot Moth (Minnesota)

Lophodermium Needle Cast Lophodermium seditiosum

Lophodermium Needle Cast, and then scroll down the page to the specific pest of interest.

Phytophthora Root Rot

Phytophthora spp.

Phytophthora Root Rot
Pine Needle Rust Coleosporium asterum

Pine Needle Rust (USDA), and then scroll down the page to the specific pest of interest.

Pine Needle Rust (North Dakota State), and then scroll down the page to the specific pest of interest.

Pine Needle Scale Chionaspis pinifoliae

Pine Needle Scale (USDA), and then scroll down the page to the specific pest of interest.

Pine Needle Scale (Minnesota)

Pine Needle Scale (Ohio State)

Pine Root Collar Weevil Hylobius radicis

Pine Root Collar Weevil (USDA), and then scroll down the page to the specific pest of interest.

Pine Root Collar Weevil (Minnesota)

Pine Root Collar Weevil (Michigan State)

Pine Shoot Beetle Tomicus piniperda

Pine Shoot Beetle (USDA), and then scroll down the page to the specific pest of interest.

Pine Shoot Beetle (Minnesota)

Pine Tortoise Scale Toumeyella parvicornis

Pine Tortoise Scale (USDA), and then scroll down the page to the specific pest of interest.

Pine Tortoise Scale (Cornell)

Sphaeropsis Shoot Blight Sphaeropsis sapinea Sphaeropsis Shoot Blight, and then scroll down the page to the specific pest of interest.
Spittlebug Aphrophora parallela

Spittlebug (USDA), and then scroll down the page to the specific pest of interest.

Spittlebug (Minnesota)

Western Pine Gall Rust Endocronartium harknessii

Western Pine Gall Rust (USDA), and then scroll down the page to the specific pest of interest.

Western Pine Gall Rust (Purdue)

White Grubs Phyllophaga White Grubs, and then scroll down the page to the specific pest of interest.
Zimmerman Pine Moth Dioryctria zimmermani

Zimmerman Pine Moth (USDA), and then scroll down the page to the specific pest of interest.

Zimmerman Pine Moth (Minnesota)

White Pine

Pest Name Scientific Name Resource Link(s)
Armillaria Root Rot Armillaria Armillaria Root Rot, and then scroll down the page to the specific pest of interest.
Introduced Pine Sawfly Larvae Diprion similis

Introduced Pine Sawfly Larvae (USDA), and then scroll down the page to the specific pest of interest.

Introduced Pine Sawfly Larvae (Minnesota)

Pales Weevil Hylobius pales

Pales Weevil (USDA), and then scroll down the page to the specific pest of interest.

Pales Weevil (Minnesota)

Pales Weevil (USDA2)

Phytophthora Root Rot Phytophthora spp. Phytophthora Root Rot
Pine Leaf Adelgids Pineus pinifoliae Pine Leaf Adelgids
Pine Needle Rust Coleosporium asterum

Pine Needle Rust (USDA), and then scroll down the page to the specific pest of interest.

Pine Needle Rust (North Dakota)

Pine Shoot Beetle

Tomicus piniperda

Pine Shoot Beetle (USDA), and then scroll down the page to the specific pest of interest.

Pine Shoot Beetle (Minnesota)

Pitch Mass Midge Cecidomyia resincola Pitch Mass Midge
White Grubs Phyllophaga

White Grubs, and then scroll down the page to the specific pest of interest.

White Pine Bark Aphid Pineus strobi

White Pine Bark Aphid (USDA), and then scroll down the page to the specific pest of interest.

White Pine Bark Aphid (Minnesota)

White Pine Blister Rust Cronartium ribicola

White Pine Blister Rust (USDA), and then scroll down the page to the specific pest of interest.

White Pine Blister Rust (Illinois)

White Pine Weevil Pissodes strobi

White Pine Weevil (USDA), and then scroll down the page to the specific pest of interest.

White Pine Weevil (Minnesota)

White Spruce

Pest Name Scientific Name Resource Link(s)
Armillaria Root Rot Armillaria Armillaria Root Rot, and then scroll down the page to the specific pest of interest.
Cooley Spruce Gall Adelgid Adelges cooleyi

Cooley Spruce Gall Adelgid (USDA), and then scroll down the page to the specific pest of interest.

Cooley Spruce Gall Adelgid (Minnesota)

Eastern Spruce Gall Adelgid Adelges abietis

Eastern Spruce Gall Adelgid (USDA), and then scroll down the page to the specific pest of interest.

Eastern Spruce Gall Adelgid (Minnesota)

Lirula Needlecast of Spruce Lirula macrospora

Lirula Needlecast of Spruce (USDA)

Lirula Needlecast of Spruce (Minnesota)

Phytophthora Root Rot Phytophthora spp. Phytophthora Root Rot
Rhizosphaera Needlecast of Spruce Rhizosphaera kalkhoffii

Rhizosphaera Needlecast of Spruce (USDA), and then scroll down the page to the specific pest of interest.

Rhizosphaera Needlecast of Spruce (Minnesota)

Spruce Gall Midge

Mayetiola piceae

Spruce Gall Midge (Minnesota DNR)

Spruce Gall Midge (Michigan State)

Spruce Needleminers

Endothenia albolineana
and

Epinotia nanana
Spruce Needleminers, and then scroll down the page to the specific pest of interest.
Spruce Sawfly Larvae (Yellowheaded Spruce Sawfly) Pikonema alaskensis Yellowheaded Spruce Sawfly
Spruce Spider Mites Oligonychus ununguis

Spruce Spider Mites (USDA), and then scroll down the page to the specific pest of interest.

Spruce Spider Mites (Minnesota)

Sudden Needle Drop (Sneed) Setomelanomma holmii Sudden Needle Drop
White Grubs Phyllophaga White Grubs, and then scroll down the page to the specific pest of interest.
White Pine Weevil Pissodes strobi

White Pine Weevil (USDA), and then scroll down the page to the specific pest of interest.

White Pine Weevil (Minnesota)