Diseases and Pests in Minnesota (MN)

Japanese Beetle (Tree)

Japanese beetles are skeletonizers, which mean they eat the “meat” of leaves, leaving only the veins behind. They also feed on both flowers and fruit. More…

Lecanium Scale

Lecanium scale represents a group of common soft scales that infest a wide range of tree species. They attach themselves to the leaves and twigs of trees and shrubs and feed on the plant nutrients. More…

Magnolia Scale

These large, easily seen insects cause damage to trees by attaching themselves to the tree’s vascular system and feeding on the sap. They can kill entire branches, and weaken the tree. More…

Oak Wilt North

Oak wilt is a vascular wilt disease caused by the fungus Ceratocystis fagacearum. This fungus grows in the water conducting vessels of the tree, which kills the tree. More…

Pine Needle Scale

Pine needle scale is a small armored scale that feeds on the sugars contained in the needles of pines, spruce and fir. The insect attaches itself to the needle and produces a hard waxy shell to protect itself from predators and environmental conditions. More…

Rhizosphera Needlecast

Rhizosphaera needlecast (Rhizosphaera kalkhoffii) is a fungal disease of spruce trees that affects trees growing outside of their native range. Rhizosphaera starts on the inner and lower growth and progresses upward through the tree. More…

Spruce Spider Mite

Spruce spider mites (Oligonychus ununguis) are among the most devastating pests of common varieties of spruce trees and other conifers. This pest is most active in the cool spring and fall when it feeds on the needles of conifers, causing a bronze or rust coloration to the needles and potential leaf drop. More…

Sycamore Anthracnose

Sycamore anthracnose is a fungal disease (Gnomonia leptostyla) that affects Sycamores throughout the United States. The fungus attacks the buds and twigs, so infected trees often have “witches brooms”

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Two Lined Chestnut Borer

Two lined chestnut borer is an insect pest that attacks oaks, beech, hornbeam and chestnuts that are stressed by drought, compaction or other insects or diseases. More…

Zimmerman Pine Moth

Zimmerman pine moth is a Lepidopteran (moth and butterfly) insect native to the northern United States. It’s larvae burrow into pine trees and other conifers and feed on the sap that is produced by the trees. More…

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