How to Manage Pests
UC Pest Management Guidelines
Scientific name: Estigmene acrea
(Reviewed 11/05, updated 1/10)
In this Guideline:
DESCRIPTION OF THE PEST
Saltmarsh caterpillar is one of the woollybear caterpillars that has long hairs covering the entire body. Their hairs are generally of sufficient density as to completely hide the skin. They are typically black at each end with a median band in between of brown or reddish brown hairs. They also exhibit yellowish spots on the sides. The hairs are called urticarial hairs and may produce a stinging dermatitis (rash) on the skin of sensitive individuals.
Caterpillars eat leaves. Young caterpillars skeletonize leaves while large, older caterpillars consume all of the leaf except the major veins. Small larvae are usually found feeding in groups on the underside of the leaves.
The eggs are attacked by a number of predators and parasites. While the dense body hairs on the larvae effectively deter some of the potential predators and parasites, larvae are attacked by several diseases.
Monitoring and Treatment Decisions
No economic thresholds have been developed for saltmarsh caterpillars, which tend to be somewhat cyclic in their nature, with damaging populations occurring every 3 to 4 years. While present in other years, numbers are generally low, and severe injury rarely occurs.
UC IPM Pest Management Guidelines:
Insects and Mites
E.T. Natwick, UC Cooperative Extension Imperial County