Disease and Pest control

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Attacks Ash, Birch, Maple and Oak

Visual Signs and Symptoms

• Large tannish-brown, lesions occur in the spring on expanding leaflets, especially along margins and veins
• Leaves may become twisted and wrinkled
• Early leaf drop, particularly from the lower parts of the canopy

Protection and Prevention

There is no cure for anthracnose once the infection has occurred, so protecting newly emerging foliage with a fungicide is the best preventative measure.  Foliar sprays with fungicides are used in the spring as leaves are emerging and again 14-21 days later to prevent infection.

Affects all Malus species, including apple, fruit trees and flowering crabapples, and mountain ash.  The apple scab pathogen overwinters in infected leaves on the ground from the previous year. In spring, overwintered spores (ascospores) mature and are discharged over a period of 5 to 9 weeks. Wind and splashing rain carries apple scab spores from infected leaves to new growth on nearby trees where new infections begin.  In late Summer or early Fall, primary apple scab infections produce secondary spores and create new infections.

Visual Signs and Symptoms

• Brown to olive, irregular-shaped spots on the leaves in late Spring
• Spots become dark and velvety in appearance
• Heavily infected leaves may become yellow and fall off the tree from late Spring through late Summer
• Fruit may also be infected by apple scab and display similar symptoms to those on leaves

Protection and Prevention

Application of a fungicide in the spring as the leaves emerge. Proper timing of the application is crucical. Fungicides properly applied will be 95% effective for treating apple scab.

Also known as Marssonina leaf spot.  Affects Aspen and Cottonwood in late Summer and Autumn.  Caused by a fungus.  Aspens are very sensitive to many pesticides, if applied incorrectly, leaves may turn black 

Visual Signs and Symptoms

• Leaves affected with the disease will be scattered randomly throughout the tree and spots will appear randomly on the leaves
• The spots are dark brown to black circles containing rings

Protection and Prevention

Rake fallen leaves in the Autumn to prevent the spread of the fungus.  Spray in the Spring when leaves are emerging from the bud.

Cedar Apple Rust is a fungus that affects cedar and crab apple trees.

Visual Signs and Symptoms

• Rains cause horn-like structures, called telia, to extrude from galls
• In drier weather the telia turn brown
• Orange blisters on leaves
• Brown rust-like structres on leaves or fruit

Diplodia shoot tip blight affects Austrian, Scots, Ponderosa, and Mugo pine, spruce and fir.  It occurs most often in well established plantings; trees 25 to 30 years old can be especially vulnerable.  Wind and rain carry the spores to young needles and buds continuing its infection progression.

Visual Signs and Symptoms

• Stunting and browning of current-year shoots in the lower branches
• Initially confined to the lower branches, progressing upward
• Stunted, straw-colored-to gray needles
• Small black dots at the base of needles and on cones

Dothistroma needle blight is a fungus which affects Larch and a wide variety of Pine.

Visual Signs and Symptoms

• Deep green bands and yellow or tan spots on needles, progressing to the ends
• Infected needles drop late-Summer to Fall

Protection and Prevention

Fungicides applied bi-annually in the growing season

Spruce Needle Drop affects Norway, white (Black Hills) and Colorado blue spruce trees.

Visual Signs and Symptoms

• Yellowing and eventual browning of older needles
• Affected branches may be scattered through the canopy
• Frequently, by autumn, all of the needles on the affected branches fall off except the newest needles on the tips of the branches

Bronze Birch Borer attacks Birch Trees.  It is recognizable by the metallic brown wings. However, the adults are rarely seen.  Bronze Birch Borer is found in Newfoundland to British Columbia, south to Colorado, Idaho, Ohio, Oregon and West Virginia

Visual Signs and Symptoms

• "D"-shaped exit holes
• Larvae under the bark and feeding galleries
• Canopy dies from the top down

Protection and Prevention

Mulching root zone and water during drought.  Minimize damage to root zone.  Application of pesticides

Conifer Bark Beetles attack Pine and Spruce.  Primarily trees which are under stress, have been freshly killed or are in the process of dying.  Up to three generations per season may occur.

Visual Signs and Symptoms

• Small white grubs with brown heads
• Brown or black beetles are usually small, up to 1/8"
• Small round holes in the bark (pupal cells)
• Tunnels and saw-dust shavings

The Eastern Tent Caterpillar attacks Prunus species such as cherry, plum, and peach, as well as flowering crabapple, hawthorn, and pear, maple, ash, birch, oak, willow, and poplar.  Eggs hatch in the spring at about the same time as leaf emergence on cherry.  Young larvae begin building their silken tents in a major branch fork or crotch for 6-8 weeks.  The pupal stage lasts for about three weeks. Adult moths emerge in early summer.

Visual Signs and Symptoms

• Stripping of the foliage in late spring and early Summer
• A silky nest is visible in the crotches of branches
• Large numbers of dark colored larvae are visible both on the tree and in the nest

Protection and Prevention

Removal of tents and branches with tents.  Spring and summer soil injections.  

Hosts of the Forest Tent Caterpillar  include aspen, oak, birch, ash, maple, elm, basswood, water tupelo, sweetgum, red alder, willow, and cherry.  Forest tent caterpillars have one generation per year.  Larvae emerge in mid-spring and the caterpillars feed for about 5-6 weeks.  In late spring and early summer, caterpillars move from feeding sites to protected area for their silky cocoons.  Approximately two weeks later, adult forest tent caterpillar moths emerge and lay shiny, black egg masses around small twigs 

Visual Signs and Symptoms

• Stripping of foliage from mid spring to early summer
• Shiny black egg masses are often visible encircling twigs
• Young larvae are black, hairy and about 1/8 inch long, often visible in groups on twigs and trunks

Protection and Prevention

Spring Soil Injection and Spray.   Most insecticides do not control these moth and butterfly insects. 

Emerald Ash Borer attacks any ash tree, regardless of age or condition.  It is recognizable by the metallic green wings and purplish red abdomen on adults.  Originally discovered in southeastern Michigan in 2002, has killed over 20 million ash trees.  Travel long distances due to human activity, i.e. firewood.  Untreated trees die 4-6 years after initial infestation.

Visual Signs and Symptoms

• Feeding galleries and larvae
• "D"-shaped exit holes
• Canopy dies from the top down
• Can take 2-3 years to become visually apparent

Protection and Prevention

Pesticide treatment within 20 mile radius of infested area.   Tree-age® is applied by a system called micro-infusion.   The chemical is delivered directly into the tree's vasculary system in order to reduce the time between the treatment and full protection.  Tree-age is currently labeled for 2 years of control.

Gypsy Moth are known to feed on hundreds of plant species, the preferred include oak, aspen, willow, linden, hawthorn, apple and alder.  Young gyspy moth caterpillars are black with orange spots on their backs.  Mature caterpillars grow up to 2" long and have five pairs of blue spots and six pairs of red spots in rows across their backs.  Pupae are tear-drop shaped and brown.

Visual Signs and Symptoms

• Holes in leaves, beginning in Spring, resulting in partial or complete defoliation by midsummer
• White, 1 ½ inches long, webby egg masses on trunks and limbs

Protection and Prevention

Soil treatment and spray in Spring and early Summer

Japanese Beetles attack Lindens, Basswood, Willows, Birch and all fruit trees.  They attract more beetles while feeding, quickly causing severe damage.

Visual Signs and Symptoms

• Skeletization of leaves

Protection and Prevention

In pre- or early infestation treat with soil injections of Transect®.  In full infestation stage we recommend a spray application to kill the beetles. This has a 14-day residual effect.  Soil injections in early spring or Fall with Xytect® causes beetles to dies after eating foliage.  Transect® and Xytect® are safe plant-based products.

Leafminers attack a variety of Birch.  Immature larvae feed individually between the leaf surfaces, creating kidney-shaped mines.  Larvae drop to the ground after about 2 weeks.  Adults emerge mid-June, lay eggs, larvae again feed for about two weeks.  The larvae drop into the soil, pupate and remain there until the following Spring.

Visual Signs and Symptoms

• Kidney shaped mines
• Damage starts at the tops of trees and the ends of branches and progressively works down and inward

Protection and Prevention

Soil injections and spray dependent upon stage

Magnolia Scale affects Magnolia, Daphne, and Virginia Creeper.  The are tiny, dark-colored nymphs.  As scales grow they are often covered with a white, mealy wax.  In the Spring, the scales begin to suck sap and have molted once by early May.  The males remain small, about 1/8-inch, and soon turn a translucent white and emerge as tiny, pink to yellow gnat- like insects with two long waxy threads extending from the tip of the abdomen.  The females continue to expand and by early June, they have turned a brownish-purple color. By July the females are covered with a powdery, white waxy coating and are shiny tannish brown and smooth, and may reach nearly ½ inch in diameter.

Visual Signs and Symptoms

• Stunted growth
• Yellowish foliage, branch dieback or even the death of the plant
• Large quantities of a sugary excretion that build up on the tree’s leaves and twigs
• Sooty mold is a black fungus that grows on that honeydew and turns the covered leaves and twigs black

Protection and Prevention

Rake fallen leaves in the Autumn to prevent the spread of the fungus.  Spray in the Spring when leaves are emerging from the bud.

Pine needle scale affects Arborvitae, Juniper, Cedar, Pine and Spruce.  Each female produces upwards to 100 eggs.  Two generations per year.  New crawlers emerge from under the scale covering of the parent scale and crawl a short distance or are windblown. 

Visual Signs and Symptoms

• White, waxy scale covering on the needles
• Red-colored eggs over-winter under the scale covering of the dead female on the needles
• Females will never develop legs, wings, eyes or antennae and never leave their waxy coverings
• Males gain the features of a typical adult insect body. Upon emergence, adult males will mate and then die

Protection and Prevention

Rake fallen leaves in the Autumn to prevent the spread of the fungus.  Spray in the Spring when leaves are emerging from the bud.

Pine sawfly feed on the new growth of all pine species, favorites are Mugoa and Austrian.  Most larvae are green or yellowish green in color with black, tan or orange head.  Adults are broad waist wasps.  Southwest typically attack open-grown trees or areas where pine is growing at a low density.

Visual Signs and Symptoms

• Eggs are laid in slits cut in the edge of living pine needles

Protection and Prevention

Timely spray with insecticides

Galls are the unusual swellings at or near the end of the branches caused by the feeding of the insects called adelgids.  The two species, the Cooley and the Eastern, attack nearly all species of spruce and the Douglas fir.  Adults are 1-3 inches long and ½-¾ inches in diameter.  Females lay between 50 and 200 eggs that hatch in about 2 weeks, at which time they begin feeding.

Visual Signs and Symptoms

• Galls caused by the Cooley adelgis are green or purple in color, begin forming in early spring and continue to grow until mid-summer, then they dry and turn brown
• Needles attached to the gall turn brown and die
• Galls caused by the Eastern adelgis resemble small pineapples and can reach up to 1½ inches in length and appear at the beginning of the current years growth as opposed to the end

Protection and Prevention

Light infestations can be controlled by carefully pruning out the galls.  Spraying in the Spring, Summer and Fall, as each treatment has benefits and limitations.

The Two-lined chestnut borer attacks Oak and Chestnut Trees.  It is recognizable by 2 thin, faint, white to golden-colored lines running down brown wings. However, the adults are rarely seen.  They are found in eastern Canada, south to Georgia & Texas, and west to the Rockies.

Visual Signs and Symptoms

• "D"-shaped exit holes
• Leaf wilting and dieback from the top of the tree downward
• Feeding galleries and larvae

Protection and Prevention

Mulching root zone and water during drought.  Minimize damage to root zone.  Application of pesticides.