Common Red Pine Bark Pests

Pinus resinosa, commonly known as red pine, is a native tree of southern Canada and the northeastern United States. These trees have a longevity reaching 350 years with heights of 100 feet common. Red pine is used in reforestation projects, lumber and pulp. While red pine does not develop many diseases as other pine do, insects and pathogens can affect it. There are five red pine bark pests that cause the most problems.

Pine Needle Scale

Scale is a common insect affecting many types of tree. Pine needle scale is specific to pine tree varieties. Observation of adults finds a wax white covering with the body generally less than 1/8 inch long. Find the eggs and larvae by looking for bright red dots that turn yellow and then tan from feeding and growing. Look for scale to attach themselves to pine needles and bark for food. Wind can spread this pest between trees. Female scales lay eggs on the needles and bark after mating. Finding sudden browning of needles is a possible sign of this red pine bark pest.

Spittlebug

Look for two types of spittlebug: the Saratoga spittlebug and the pine spittlebug. These red pine bark pests attach to twigs to feed. Their name is derived from the mass surrounding the insect called spittle. Affected twigs often die and their appearance is found near the crown of the tree. Spittlebugs look for new growth to feed on.

Pine Sawfly

Find this insect in young red pine. Red pine growing in poor soil, dense undergrowth or underneath the shadow of hardwood trees are most prone to the red-headed pine sawfly. A single female sawfly can lay 120 eggs. Sawfly eggs are found in slits along pine needles. Larvae reach maturity within one month. Once grown, the sawfly falls to the ground and spins a cocoon; the cocoon lasts for three weeks. Once emerged, the sawfly lays more eggs. Look for stunted growth and deformity from trees affected by this pest. Treat the tree with chemical pesticides once larvae are hatched.

Minor Pests

Three other red pine bark pests that can cause deformity in red pine include the Red Pine shoot moth, the pine root collar weevil and the pine engraver. Look for deformities in upper branches and developing pinecones as signs of the Red Pine shoot moth larvae. Girdled trees may be a sign of the pine root collar weevil. The larva of this pest feed upon inner bark of the collar and roots which is how this pest gets its name. Affected trees can die within five years of the first attack of the root collar weevil. Signs of the pine engraver include exit and entry holes in adjacent trees. Adult pine engravers bore into the bark, mate and then construct egg chambers. The larvae feed on wood until they are grown and then move to the next tree.

Pathogens

Pathogens that infect red pine trees take the form of fungus. Three common fungi are the lophodermium needle cast, pine needle rust and diplodia shoot blight. Find the first of these fungi on nursery seedlings that suffer from defoliation; look for spores on dead needles. Pine needle rust is found where alternate hosts exist as ground cover around the pine stand such as goldenrod. This fungus develops spores on pine needles that are carried to the secondary host to form more spores; these spores are then blown back to the pine trees to start the process again. Look for diplodia on pine needles and cones. This fungus moves via rain splashes onto trees. Control of these fungi pathogens is often by the use of fungicide and controlling surrounding growth.

Lophodermiurn needle cast is a fungus that damages many nursery seedlings by defoliation. Spores can be found on the dead needles, and can affect neighboring trees. Pine needle mulch that includes spores can also be a source for spreading the fungus.

Sources:

Michigan Society of American Foresters

Penn State University