From the Beaufort County Cooperative Extension Master Gardeners

Over the past couple of years, this region experienced a huge infestation of the nasty little moth, Hyphantria cutea, and the resulting webbed nests that the moth’s larval stage constructed.

Draped over a wide variety of deciduous trees and shrubs, the light gray, silky webs literally overwhelmed large expanses of Beaufort County woodlands. Trees were covered in the little pests’ nests!

Primarily seen as a cosmetic issue, fall webworms are not considered harmful to robust woodlands. Aesthetically, they are disfiguring and most homeowners are willing to do just about anything to be rid of the unsightly webs that mar the resplendent foliage of their hardwood trees. The webworms are found in America, Canada, Mexico, Europe, Korea and Japan. The Europeans consider it a worse pest than the infamous Gypsy Moth.

Normally, this pest tends to have periodic outbreaks. They will normally appear every four to seven years and last for several years. Webworm nests enclose branch tips and leaves of more than 85 species of hardwood trees and many deciduous varieties of shrubbery. The caterpillars begin to eat leaves within the nest late in the season. If the food runs out, the nests are expanded. The pest will overwinter in the pupil stage. You can find them on the ground, lodged in the bark of trees or inside old nests. The adult emerges in the early summer. Eggs are deposited on the undersides of leaves. The eggs will hatch in about a week. The caterpillars will eat the leaves and skeletonize the leaf structure. The larvae mature in about a month, drop out of the nest and fall to the ground and pupate. Adult moths emerge and the process begins again. Many generations will be developed over the summer and into the fall.

The fall webworm is a medium-sized, white insect that has black spots on its body. The eggs of these insects are laid in masses of several hundred. Once hatched, the pupa changes to dark brown. These creatures are sometimes mistaken for tent caterpillars. The tent caterpillar, however, has nests in the crotches of trees.

Although unsightly, the nests are not extremely damaging to woodlands. Smaller nests can be cut out of canopies. Do not “burn” them out as it is highly injurious to the host tree and can be dangerous. Forest fires are easily started in this manner. Bacillus Thuringienisis (BT), a bacterial insecticide can be applied in the early stages of development. Upon ingesting leaves coated with BT, the larvae die. Nature employs wasps, birds, and yellow jackets and stink bugs to attack the caterpillars in the nest and control their proliferation. Forewarned is forearmed!

Kay Graham is a certified Master Gardener volunteer. The information for this article is given courtesy of the Extension Master Gardeners who are volunteers under direction of the Beaufort County Cooperative Extension. They are available to answer your questions concerning lawns, vegetables, trees, ornamentals, fruits, plant problems and diseases, pests, soil and many other horticulture issues relating to gardening in North Carolina. Reach a Master Gardener through the Hot Line at 252-946-0111 where you can leave a voice message or email the Master Gardeners your question at beaufortcomg@gmail.com and a volunteer will respond to you inquiries.

 

 

Gardening Calendar September

Lawn Care

• Now is the time to fertilize and lime your tall fescue according to the soil samples.
• There is no need to fertilize warm season grasses.
• Grubs in turf can be controlled with insecticides at the beginning of this month.

Fertilizing

• There are no fertilizing needs this month other than cool season grasses.

Planting

• Vegetables to be planted in September: mustard, onions, radishes, and turnips.
• Set out new chrysanthemum plants this month.
• Now is a good time to set out or transplant landscape plants. Be sure to “open up” the root balls of container plants.
• Pansies can also be set out this month to add color to the landscape.

Pruning

• Long-blooming annuals and perennials can be cut back.

• Late summer is NOT a good time to prune trees and shrubs because pruning will stimulate new growth.
• Dead or diseased wood can be pruned out anytime of the year.
• Weeds or unnecessary trees should be removed from the landscape.
• Root prune any plants you plan to move next spring.

Spraying

• Watch shrubs for the following insects: spider mites, scale, and lace bugs.
• Use recommended herbicide to control trumpet creeper, and blackberry.
• Continue with rose spraying program.
• Peach and nectarine trees need a trunk spray for peach tree borers.
• Insects and diseases can be more severe in the autumn, keep a close eye on your fall vegetables.

• Note: (Pesticides should be used sparingly! Use only when needed and always follow the label)

Other Activities

• Prepare houseplants to reenter your home. Check them carefully for insects.