Tree Damage Identification

  1. Aphids


    Aphids, commonly known as plant lice are small, pear-shaped, fragile insects

  2. Apple Maggot

    Apple Maggot

    Apple maggot (Rhagoletis pomonella) is a pest fly native to North America, and has been a serious pest of apples in Canada for over 100 years.

  3. Ash Borer

    Ash Borer

    The ash borer or lilac borer (Podosesia syringae) is a day-flying clearwing moth native to North America. The larvae feed on the bark and wood of ash trees and lilacs.

  4. Ash Leaf Cone Roller

    Ash Leaf Cone Roller

    The adult of the ash leaf cone roller (Caloptilia fraxinella) is a small gray moth with a 12 mm wingspan. This insect is native to North America.

  5. Birch Leafminers

    Birch Leafminers

    Three species of sawflies (Fenusa pusilla, Profenusa thomsoni, Heterarthrus nemoratus) introduced from Europe in the early 1970s can be responsible for the premature browning of birch trees

  6. Black Knot

    Black Knot

    Black knot (Apiosporina morbosa) is a fungal disease that causes greenish brown to black swellings in the stems of cherry trees (Prunus spp.).

  7. Bronze Birch Borer

    Bronze Birch Borer

    This beetle (Agrilus anxius), native to North America, is 7-11 mm in length and dark green-bronze in color.

  8. Bronze Leaf Disease

    Bronze Leaf Disease

    The disease will develop over the summer and infections will spread internally to other parts of the trees. Symptoms typically appear in later summer (early-mid August) or early fall (September) Bronze Leaf Disease

  9. Bruce Spanworm

    Bruce Spanworm

    Bruce Spanworm overwinters as eggs laid singly on twigs. The eggs hatch near the green tip stage of apple.

  10. Cooley Spruce Gall Adelgid

    Cooley Spruce Gall Adelgid

    Adelgids are a small group of insects that are closely related to aphids

  11. Cottony Psyllids on Ash

    Cottony Psyllids on Ash

    The cottony psyllid (Psyllopsisdiscrepans) belong to the family of insects sometimes called jumping plantlice.

  12. Dothiorella Elm Wilt

    Dothiorella Elm Wilt

    Dothiorella elm wilt is a disease involving a fungus (Dothiorella ulmi) that causes the wilting and progressive die-back of American and Siberian elm trees.

  13. Dutch Elm Disease

    Dutch Elm Disease

    Dutch Elm Disease (DED) is a deadly disease caused by a fungus (Ophiostoma ulmi) that can affect any elm tree.

  14. Elm Scale

    Elm Scale

    European elm scale (EES) is a pest that normally attacks fruit and ornamental trees.

  15. Forest Tent Caterpillars

    Forest Tent Caterpillars

    The forest tent caterpillar (Malacosoma disstria) is a pest of broad-leaved trees and shrubs. Young caterpillars are black, hairy and about 3 mm long. They cluster together on the trunk or branches when they are not feeding.

  16. Larch Sawfly

    Larch Sawfly

    The larch sawfly can be detected by looking for the slits on new shoots in which females have deposited their eggs or checking for groups of larvae crawling on the branches

  17. Large Aspen Tortrix

    Large Aspen Tortrix

    The large aspen tortrix is one of the main insects associated with the trembling aspen. This species occurs throughout the geographic range of the trembling aspen, its preferred host.

  18. Larger Boxelder Leafroller

    Larger Boxelder Leafroller

    The larger boxelder leafroller (Archips negundana) is a green caterpillar found on Manitoba maple (boxelder) trees during spring and early summer.

  19. Linden Looper

    Linden Looper

    The linden looper overwinters in the egg stage on host trees. In May, or as soon as the buds begin to open, the larvae emerge and begin feeding on the new foliage.

  20. Pine Webworm

    Pine Webworm

    Females lay eggs on needles. After hatching, pale green larvae mine the needles. Older larvae live in silk tubes hidden inside a mass built of silk and frass.

  21. Pitch Moth

    Pitch Moth

    Pitch moth larval feeding causes infested conifers to produce copious amounts of resin that form globular masses on bark.

  22. Porcupine Damage

    Porcupine Damage

    Porcupines can cause significant damage to personal and public property by feeding on trees.

  23. Satin Moth

    Satin Moth

    The caterpillars feed principally on the leaves of poplar and willow trees and less commonly on oak

  24. Spruce Beetle

    Spruce Beetle

    Spruce beetles occur in endemic populations in white spruce stands throughout Alberta.

  25. Spruce Spider Mite

    Spruce Spider Mite

    The spruce spider mite (Oligonychus ununguis) is a common pest found on spruce trees. Adult mites are green-brown, have 4 pairs of legs and are scarcely visible to the unaided eye.

  26. Uglynest Caterpillar

    Uglynest Caterpillar

    The insect is named after its untidy, nest-forming characteristics. Larvae of the ugly nest caterpillar hatch from overwintering eggs in the spring and may be found feeding throughout May to September.

  27. Ungulate Damage

    Ungulate Damage

    Bucks rub their antlers on small, flexible trees in order to rub off the velvet that initially covers them. During rut, bucks rub their antlers on trees to attract receptive does and to demarcate territory and warn other bucks to stay away.

  28. Western Gall Rust

    Western Gall Rust

    Infection by western gall rust results in round or pear-shaped galls on branches or stems of susceptible pine hosts.

  29. Yellow-bellied Sapsucker

    Yellow-bellied Sapsucker

    Yellow-bellied Sapsuckers are fairly small woodpeckers with stout, straight bills.

  30. Yellowheaded Spruce Sawfly

    Yellowheaded Spruce Sawfly

    The yellowheaded spruce sawfly (Pikonema alaskensis) is native to North America. Mature larvae are about 20 mm (3/4 of an inch) long. They look like hairless green caterpillars with a series of darker stripes running along the body. They have a distinctive dark yellowish head.