Blackheaded fireworm eggs overwinter on the bed. It is important to catch the first generation, if possible, because the second generation occurs during bloom and is typically much more destructive. Larvae can be detected by sweep sampling and it is good idea to look along the edges of bed where vines first begin to grow. First-generation larvae feed on terminal foliage, webbing them together (see pictures).
Feeding can cause vines to appear as if burned. This insect can be detected by looking for webbing in the upright tips.