Insect Pests of Christmas Trees

	The pine bark adelgid is a serious pest of eastern white pine and is conspicuously noted by its cottony covering.
	Pine b. adelgid causes excess bud formation leading to proliferation of shoots at the top of the tree. Note also the lady beetle feeding on the adelgids.
	Pine bark adelgids also feeds at the base of needles. These cotton masses are the most conspicuous but usually the least damaging.
	Dormant oil sprays in late winter provide effective control but may slightly discolor the tree as seen in this slide.
	Spruce trees growing in close association with Douglas-fir often have the Cooley Spruce Gall Adelgid. In this slide, the Douglas-fir is on the left; spruce is on the right.
	This is an example of the Cooley Spruce Adelgid found on spruce. This is as the gall would appear in early summer or late fall. It was green earlier in the summer.
	Heavily galled trees become disfigured and have reduced value as Christmas trees.
	Spruce trees in the foreground with Cooley Spruce Gall Adelgid with Douglas-firs in the background. The Douglas-firs are the alternate or winter host for this adelgid.
	A closely related gall is the Eastern Spruce Gall Adelgid, a common pest on both Christmas trees and yard plantings. Note the short needles on the gall.
	Another shot of the Cooley Spruce Gall Adelgid. Note the long needles on the gall itself. Both the Eastern and Cooley Spruce Galls can be controlled with either a dormant oil application in late winter or a registered insecticide in late summer just as the galls turn brown and open up.
	The bagworm is a serious pest of Christmas trees, nursery trees, and yard plantings. Note the defoliation on top of this fir tree.
	Close up of the bagworm, full-grown larval stage. The bagworm is a caterpillar that lives inside a silken bag. To this bag it attaches plant material from its host plant. In late summer, it permanently attaches itself to the host tree on a small branch.
	This is a cross section of a gall caused by the silk of the bagworm. At the end of the summer, it places a band of silk around a small twig so that it can attach itself for pupation. This silk often lasts for years and cuts off circulation for the tree, resulting in this type of a gall.
	Top view of the same gall. This gall is approximately two years old.
	Overwintering bag of the bagworm cut open. The overwintering stage is an egg mass inside old bags. This offers an excellent opportunity for control as these bags filled with eggs can be picked off and destroyed.
	Cambium Miner on White Pine. This small fly makes small tunnels just under the bark of twigs. This insect does not cause damage to the tree.
	Another minor pest of Christmas trees is Japanese Beetles, which chew small holes in tender young twigs. This feeding leaves a wound where small amounts of resin collect. The resin dries, leaving small white spots on the bark.
	This is the Pine Spittle Bug, a sporatic pest on Scotts Pines and other Christmas trees. Inside this Spittle mass is a small insect feeding with piercing, sucking mouthparts. This damage is usually inconsequential, but can result in twig death in some cases. The twig will usually turn light green, then yellow, and then turn brown and die.
	Sooty mold which is often found in association with Spittle Bug feeding. Note the cast skin of a Spittle Bug on the end of the needle.
	More sooty mold associated with Spittle Bug.
	Discolored shoots associated with Spittle Bug feeding.
	The Spruce Spider Mite is a serious pest of Fir, Spruce, and Hemlock. Its typical damage is to causes a stippling effect on the needles, causing them to loose color and turn yellow.
	A close up of Spruce Mite damage on Arborvitae. Note the red eggs, the clear egg shells, and the green mites. In addition, notice the spots caused by the feeding.
	Spruce Mite damage on Fraser Fir. Note the bare earth underneath the tree. This acts as a reflective heat source enhancing the mite problem. If possible, allow vegetation to grow under and near trees.
	Scots Pine seriously damaged by the Nantucket Pine Top Moth. Note the rounded, stunted growth.
	Close up of twig damage from a Nantucket Pine Tip Moth.
	Bud damage from a Nantucket Pine Tip Moth. Note hole down the center of the bud.
	Additional Nantucket Pine Tip Moth damage. Note resinous bleeding at base of bud.
	Stunted branch with much damage from the Nantucket Pine Tip Moth.
	Area of Christmas Tree plantation with heavy damage by the Nantucket Pine Tip Moth.
	The Pales Weevil is a serious pest of many conifers. In this particular case, the shoot death on this Douglas-fir has been caused by Pales Weevil feeding.
	Close up of Pales Weevil damage on a White Pine shoot. White Pine is the Pales Weevil's preferred host.
	More damage on White Pine causes by Pales Weevil.
	Lone branch killed by Pales Weevil feeding. This type of damage is called flagging.
	White Pine with much flagging from Pales Weevil.
	Ideal situation for Pales Weevil problems. Note the pine stump in the foreground which is a breeding site for immature Pales Weevils. In the background are Eastern White Pine trees which act as a food source for adult Pales Weevils. Pales Weevils are also important for the transmission of Procerum root disease.
	Feeding damage caused by White Pine Weevil. This insect feeds on the tops of White Pines and Norway Spruce. Feeding by larvae causes the leader and the top whorl to die.