Most recently reviewed by: Ballinger (Vacant) & & Pat Porter (2021)
Common Name(s): puss caterpillar, Southern flannel moth
Eggs are small, elongate with rounded ends. The are laid in rows or clusters on foliage or small twigs and are covered with hairs from the female moth.
Larvae vary in size and color based upon stage/ instar. Early instars are yellow in color with spiny hairs emerging from the base of the body. Larvae change and become more hairy as the grow larger. Mature caterpillars are brown to gray in color, teardrop shaped with soft looking hairs covering the body. While the caterpillars look soft, you do NOT want to touch them as they can sting.
Pupae/ cocoons are typically found on plants, but mature larvae may wander from the host plant and onto adjacent plants or surfaces. Cocoons are spun from silk and are creamy white to light brown in color. They are flattened toward the front and have a hump towards the back. Cocoons are tough and may remain on the plant after the adult has emerged.
Adults are small, hairy moths with a 1-1.5 inch wingspan, with females being larger than males. Front wings are yellow and hind wings are creamy yellow. Bodies are covered with thick hair that looks like fur and is yellow to orange in color.
Origin and Distribution
Asp caterpillars can be found from the east coast, down to Florida and west to Texas.
Habitat & Hosts
Eggs, larvae, and pupae are found on plants. Larvae feed on foliage of a variety of plants, but are commonly found on oaks.
Complete life cycle: egg- larva- pupa- adult
Eggs are laid on foliage and small twigs of host plants by mated females that recently emerged from their cocoon. Eggs are laid in rows or sometimes in patches and are covered with hairs from the underside of the the female moth’s abdomen. Larvae are found on host plants where the feed on foliage. Mature larvae may wander from the host plant to adjacent plants and surfaces to pupate. There are two to three generations per year.
ManagementIf you live in the State of Texas, contact your local county agent or entomologist for management information. If you live outside of Texas, contact your local extension for management options.
Larvae are the damaging stage. While larvae feed on foliage of plants, usually they are not problematic for the plants they feed upon. Large populations can defoliate plants. Typically, these caterpillars are kept under control by natural enemies, such as tachinid flies or ichneumonid wasps. If a pesticide treatment is warranted, look for active ingredients such as Bacillus thuringiensis var. kurstaki or spinosad to reduce harming beneficial insect populations.
Concern for larvae is for their capability to sting. All stages of caterpillars can sting (as well as the shed exoskeletons), but severity of the sting increases as the size of the caterpillar increases. Asp caterpillars have spines that are hollow and contain venom. These spines can break off into skin and cause an immediate stinging sensation, reddening at the site and sometimes localized swelling. More severe reactions may include headache, nausea, fever, racing heartbeat, abdominal pain, seizures, or other issues.
If you are stung, remove spines with sticky tape and try alleviating symptoms by using ice packs, oral antihistamines, and topical hydrocortisone cream. If you are stung by an asp caterpillar and have a severe reaction, seek medical attention immediately.