Bald-faced hornet Bald-faced hornet Dolichovespula maculata is a eusocial wasp of the cosmopolitan family Vespidae. Its colloquial names include the bald-faced hornet, bald hornet, white-faced hornet, white-tailed hornet, spruce wasp, blackjacket, and bull wasp. This species is a yellowjacket wasp, not a true hornet (genus "Vespa"). Colonies contain 400 to 700 workers, the largest recorded colony size in its genus, "Dolichovespula". It builds a characteristic large hanging paper nest up to 58 centimetres (23 in) in length. Workers aggressively defend their nest by repeatedly stinging invaders. "Dolichovespula maculata" is distributed throughout the United States and southern Canada, but is most common in
Bald-faced hornet colonies have been observed in central Pennsylvania as late as mid-October. The colony is founded by a single overwintered, inseminated queen. She rears the first generation of workers on her own until they are functional. Colonies pass through the foundation over an average period of 23–24 days. After the queen lays her eggs, it takes 6 days for them to hatch. They grow as larvae for eight days. It takes them an additional 9–10 days to mature into adult workers. During the ergonomic stage, the colony's activities are concerned with cell building and worker production. The queen devotes herself entirely