How to Manage Pests
UC Pest Management Guidelines
Saltmarsh caterpillar early instars are various shades of yellow-brown with long, dark hairs. Older caterpillars are densely covered with black and red hairs and often have yellow stripes running lengthwise down their bodies. Adult moths have white wings with numerous black spots on the upper surface and yellow on the undersides. These caterpillars are uncommon in lettuce unless they build up on a neighboring crop of cotton, bean, etc., and move into lettuce.
Larvae feed on leaves and have caused economic losses in the past.
To stop migrating saltmarsh caterpillars, place a barrier such as a strip of heavy aluminum foil about 6 inches high set on edge in the soil, or an irrigation ditch filled with water.
UC IPM Pest Management Guidelines: Lettuce