In the Auburn vicinity, in east-central Alabama, oviposition usually begins during the last half of July and extends well into August. Eggs hatch in about one week, and in the Auburn vicinity, early stage larvae are present by or during the first week of August. As larvae grow, body color changes. There are two long black spines on the second segment of the thorax and short, sharp black spines along the back and sides of the body. The prominent long spines on the thorax are characteristic of the genus.
Spiracles are black, and each is enclosed by a white margin.
Larvae are aggressive feeders, and generally consume all but stubs of midrib and large veins of leaves. Larvae are often present until early October. Fully grown larvae enter the soil, pupate, and overwinter in the pupal stage. One generation occurs each year. Throughout development, larvae are exposed and vulnerable to parasites and predators, and these sometimes cause considerable oakworm mortality.