• Latin Name: Estigmene acrea
  • Latin Family Name: Erebidae
  • Common Name: Salt Marsh Caterpillar
  • Other Names: Salt Marsh Moth, Woolly Bear Caterpillar, Acrea Moth

Origin:
This is a native moth in North America.

Biology:
This common moth is found throughout Canada, the U.S., and into Mexico. The larva is a familiar furry caterpillar found as it rapidly runs across patios and walkways. The larvae have an amazing ability to feed on just about anything, including many weeds such as pigweed, fennel, mallow, and nightshades, as well as a great many ornamental shrubs and trees and crops such as apple, cherry, tobacco, tomato, onion, lettuce, corn, and many others. Mature larvae overwinter and resume activity in the spring when they pupate. There will be from 1 to 4 generations per year depending on the temperature and region. Females deposit eggs in one or two clusters with up to 1,200 eggs in a single cluster, attached to the host plant. A generation will be completed in just over a month and adult moths may be active year-round in southern states.

Identification:
The larva varies considerably in its ground color, from light tan to brown to black, and with tufts of long dark hairs occurring over its body. These become denser as the larva matures and vary from black to orange to white, with longer hairs at the front and the rear. The adult moths differ from male to female, with males having dark yellow hind wings while female’s wings are all white. There are about 2 dozen black spots scattered across the forewings.

Characteristics Important to Control:
The use of chemical sprays is often necessary to kill the larvae, including both synthetic insecticides as well as natural materials such as Bacillus thuringiensis. Sprays should be directed onto the larvae when first noticed on the plants. These often occur as only a few larvae and will cause insignificant damage.