Bagworms often appear as small cones on the plants on which they feed. They spin silken bags around themselves, to which they attach pieces of the specific host plant that they are consuming for camouflage. Full grown, they can measure nearly two inches in length, though while young they can go nearly unseen. The females lay their eggs in fall, and the eggs hatch the following spring.
Bagworms should be controlled as soon as they are noticed, as large numbers can quickly defoliate a tree. An insecticide spray is recommended in early June through July when they are most ravenous. If bagworm infestations are an annual problem, a systemic, water-soluble insecticide can be applied in late February and March to protect plants throughout the year.

Eastern Tent Caterpillars emerge from a shiny dark egg mass that encircles the fine twigs on the trees upon which they feed. They build silken tents on branches of host plants, where they reside while consuming the foliage. The appearance of webbing (tents) may be the first evidence of the tent caterpillar’s coming feeding frenzy. This tent will quickly expand as the growth of these voracious caterpillars increases. Full-grown larvae are hairy and black with white stripes on their backs. Narrow brown and yellow lines and a row of blue spots are visible along their sides.

Systemic control in early spring can be used to control this aggressive feeding insect. Insecticide sprays may be necessary to control these pests. Preferred host plants are cherry, crabapple, and apple trees.

Scale There are many different types of scale insects that attack many different host plants. These pests have waxy, hardened shells, which protect them while feeding. Some scale feed on the undersides of leaves and needles, while others feed on twigs. Damage is first evidenced by the leaves or needles turning slightly yellow and falling prematurely. Weak host plants are the most vulnerable.

This pest should be controlled the first year it is noticed, as it can significantly weaken an infested host plant. A non-toxic dormant spray can be applied in late March to kill eggs and emerging larvae, or the host plant can be injected with insecticide capsules between spring and fall. Along with destroying this pest, an infested host plant should be reviewed, as it may need other supplemental care such as feeding or irrigating. Common infested host plants include spruce and pine, as well as poplar and magnolia.

Fall Webworms Much like eastern tent caterpillars, the tents of the fall webworm are often visible before the pests can be readily seen. Fall webworms build silken webs on branches of host plants, where they reside while consuming foliage. Young larvae are pale yellow with two rows of black marks along their bodies. Full-grown larvae are green and covered in white hairs, which protrude from orange and black spots. They sport a yellow stripe along their sides.

Fall webworms are unsightly and can cause structural damage as a result of the wind stress created from their large webs. Their feeding cycle occurs at a time when glucose production is essentially completed and does not represent a major stress for trees. They can be controlled with aerial sprays or root drenching with water-soluble solutions. Their preferred host plants are walnut, hickory, birch, cherry, and crabapple trees.

Canker is a fungal pathogen. There are many different types of this fungus that attack different host plants. Some result in visible cankers. Cankers appear as open bark lesions, which vary vastly in size, eventually swell, and girdle infected portions of host plants. Weak host plants are the most vulnerable. Infected branches should be removed and burned when possible, and infected host plants should be injected with fungicide capsules between spring and fall. Along with treatment of the fungus, an infected host plant should be reviewed further, as it may need other supplemental care such as feeding or irrigating. Common host plants include, but are not limited to azalea bushes and maple, willow, crabapple, and dogwood trees.

Bacterial Leaf Scorch(BLS) is a bacterial plant disease that affects a wide variety of trees, particularly those of the red oak family. The disease is caused by a bacterium that clogs the infected trees’ xylum and interferes with their ability to take up water. The first symptoms of this disease often appear in late spring or early autumn, and they often mimic the effects of heat stress or drought. Leaves usually exhibit a scorched or burned appearance, especially on the edges and between the veins, which progresses to twig and branch dieback.

While BLS is not a new disease, it has recently become epidemic in our area, and it has caused the death of countless majestic trees in a relatively short period of time. The most effective treatment currently available to combat BLS is trunk injections of antibiotics to suppress the bacterial agent and growth regulators to maximize the trees’ use of resources, combined with regular watering, nutritional support and specially timed pruning to remove dead and infected wood. In some cases it may also be beneficial to employ insect control mechanisms to combat insects such as leafhoppers and treehoppers that are known to transfer this bacterial agent from infected plants to healthy ones.

Because the early symptoms of BLS mimic other common stress agents in trees, laboratory confirmation of a diagnosis of BLS is highly recommended. Our technicians can retrieve samples and submit them for expert laboratory analysis.