Saltmarsh caterpillar—Estigmene acrea
Adult moths have a wing expanse of 5 to 6 1/2 cm. The female is white, except for an orange abdomen with black lateral and dorsal spots and black spots on the wings. Hind wings of males are orange instead of white. Caterpillars are very hairy with conspicuous tufts of long hair on each segment.
Saltmarsh caterpillars overwinter as fully grown larvae. Pupation occurs in early spring. Adults emerge in 10 days to 3 weeks and then mate and lay eggs, nearly always on lower leaf surfaces. In warm spring weather, egg hatch occurs in a week to 10 days. Eggs are pearly white to creamy yellow. Young larvae are light buff with clusters of long, dark hairs over the body. As they increase in size, they become more hairy. Mature larvae pupate in 4 to 5 weeks, usually under leaf trash in the soil. Adults emerge in 10 days to 2 weeks, depending on weather. A generation may be completed in about 6 weeks during warm summer weather. There are three to four generations a year, the fall generation being the most numerous and most destructive.
Young larvae feed in groups on the underside of leaves; leaf veins and the leaf surface remain intact.
Older larvae feed independently, eating through leaves and leaving the foliage ragged.
The saltmarsh caterpillar has many natural
enemies and seldom requires special control practices. Bacillus
thuringiensis or spinosad are effective
against very small caterpillars.
Second and fifth instar caterpillars