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 the queen's brood. In a sampling of seven "D. maculata nests", 20.9% of males were produced by workers. The percentage of males who were workers’ sons did not correlate with the time during which nests were collected or colony size. Because worker relatedness is so high in "D. maculata", workers are more related to other workers' sons than to the queen's own sons, and therefore worker policing of egg production does not occur. An explanation for the queen's near monopoly on male production is that worker production is costly and therefore reduces total colony reproduction. The cost toward worker production