Bald-faced hornet

Description

Dolichovespula maculata is a species of wasp in the genus Dolichovespula and a member of the eusocial, cosmopolitan family Vespidae. It is known by many colloquial names, primarily bald-faced hornet, but also including bald-faced aerial yellowjacket, bald-faced wasp, bald hornet, white-faced hornet, blackjacket, white-tailed hornet, spruce wasp, and bull wasp. Technically a species of yellowjacket wasp, it is not one of the true hornets, which are in the 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 cm (23 in) in length. Workers aggressively defend their nest by repeatedly stinging invaders. The bald-faced hornet is distributed throughout the United States and southern Canada, but is most common in the Southeastern United States. Males in this species are haploid and females are diploid. Worker females can, therefore, lay eggs that develop into males. The bald-faced hornet is distinguished from other yellowjackets by its white and black coloring. It has a white or "baldfaced" head, which is the source of its colloquial name. This wasp also has three white stripes at the end of its body and is notably larger than other species of Dolichovespula, as adults average about 19 mm (0.75 in) in length. Queen and worker wasps have similar morphologies. Queens are always larger than workers in their colonies, though size distributions can vary in different nests, and workers in one colony might be as large as a queen in a different one. D. maculata creates egg-shaped, paper nests up to 360 mm (14 in) in diameter and 580 mm (23 in) in length. Nests are layered hexagonal combs covered by a mottled gray paper envelope. Bald-faced hornets create this paper envelope by collecting and chewing naturally occurring fibers. The wood fiber mixes with their saliva to become a pulpy substance that they can then form into place.