Bagworm injury is frequently overlooked early in the season when the bags are small. By the time actual feeding is noted, these pests have developed to a stage where they are difficult to control with chemicals.

Eggs remain in the bag over winter. These eggs hatch in the spring - about mid May in the eastern area. The young larvae (caterpillars) begin to feed immediately after hatching and build a bag or "cocoon" lined with silk and having leaves and stems of the host plant on the outside. This cocoon gets bigger as the caterpillar develops. It reaches full size about mid-August. The caterpillar takes its protective bag wherever it goes.

The larvae change to pupae within the cocoon. The male moths leave the cocoon from late August to early November. They are almost black in color with a furry body and feathered antennae. Their wing spread is about one inch. The females are more or less maggot-like, white in color and never leave the cocoon. Each fertilized female produces 500-1,000 eggs in the cocoon or "bag" before she dies.

Where it is practical, it is advisable to remove and burn the cocoons. Scissors or a sharp knife may be used. Chemical treatments are very effective if applied while bags are still small and not attached. This is usually the last of June until mid July.

Apply sprays of acephate (Orthene), Bacillus, chlorpyrifos (Dursban) diazinon, malathion, Carbaryl (Sevin) or Trichlorfon (Dylox/Proxol) as soon as infestation is noted and again seven to ten days later. Thorough coverage is essential.

Now is also the time to spray for most scale insects. The crawler stage is present now and is very susceptible to insecticides and heavy rain damage. Orthene, Sevin, diazinon, and malathion are the most available insecticides to use. As always, follow label directions for mixing and safety to non target life -- including yourself.

DISCLAIMER: Recommendations for use of chemicals are included in this newsletter as a convenience to the reader. The use of brand names and any mention or listing of commercial products or services does not imply endorsement by the N.C. Cooperative Extension Service nor discrimination against similar products or services not mentioned. Individuals who use chemicals are responsible for ensuring that the intended use complies with current regulations and conforms to the product label. Be sure to obtain current information about usage and examine a current product label before applying any chemical.

Revised 2/16/2006.