Caterpillars in Your Yard and Garden
Prominents and oakworms
Yellownecked caterpillars (Datana ministra) are present from July to September. They produce one generation per year.
Full-grown larvae, nearly two inches long, have black heads and an orange-yellow prothorax ("neck" region). The body is black with several longitudinal white stripes, and is lightly covered with long, white hairs. The lateral sides of the thoracic legs and the abdominal prolegs are orange. Host plants include a variety of fruit, shade and forest trees, especially apple and oak.
About the family
Prominents and oakworms belong to the Notodontidae family. Caterpillars have variable color patterns and body texture. Some species are smooth with fleshy humps or projections while others are hairy. Some are cryptically colored, mimicking the edge of a partially eaten, distorted leaf, while others are brightly colored and conspicuous. In some species, when the caterpillars are disturbed, they raise both ends of the body, holding onto the substrate with the four mid-abdominal prolegs and exposing glands that produce irritating acidic chemicals to ward off potential attackers. Caterpillars exhibit both solitary and gregarious behavior. Host plants include a wide variety of trees and shrubs.