Colonies pass through the foundation over a typical period of 23–24 days. She rears the first generation of workers on her own until they are functional. The colony is founded by a single overwintered, inseminated queen. On October 28, 2022, an active colony was encountered on the Middle Fork Willamette River in western Oregon. Active colonies have been observed in central Pennsylvania as late as mid-October. These nests survive between 155 and 170 days. In Indiana, colonies have been observed to begin in early May and terminate in late September, a life cycle of 5 months (153 days), and in Central California, nests are initiated as early as the end of March. Lower latitudes correlate with longer life cycles. The colony terminates during mid-September, for a life cycle around 4 months (122 days). Large-cell building starts during mid-July, and the first queens emerge during mid-August. In Washington, nest initiation occurs during mid-May, and workers emerge during mid-June. New nests are generally founded during spring and early summer by a single queen, though temporal specifics vary depending on location. The life cycle of a colony can be divided into the founding stage, the ergonomic stage, and the reproductive stage.

The venom causes immediate watering of the eyes and temporary blindness. The bald-faced hornet has a unique defense in that it can squirt or spray venom from the stinger into the eyes of vertebrate nest intruders. They vigorously defend the nest, with workers stinging repeatedly, as is common among social bees and wasps. Their aggressive defensive nature, though, makes them a threat to humans who wander too close to a nest or when a nest is constructed too close to human habitation. Behavior īald-faced hornets are omnivorous, and considered to be beneficial due to their predation of flies, caterpillars, and spiders. Vertical distribution of nests has been recorded from heights of 0.3 to 20 m (1 ft 0 in to 65 ft 7 in) above ground level. Nests are generally located in trees and bushes, but occasionally are found under rock overhangs or the sides of buildings. maculata is found in forested areas and in vegetation in urban areas. It is most common in the Southeastern United States. The bald-faced hornet lives in North America, including Canada, the Rocky Mountains, the western coast of the United States, and most of the eastern United States. This view, with paper outer wall removed, shows the final, small comb that hangs at the bottom.ĭistribution Dolichovespula maculata distribution The wood fiber mixes with their saliva to become a pulpy substance that they can then form into place. Bald-faced hornets create this paper envelope by collecting and chewing naturally occurring fibers. Nests are layered hexagonal combs covered by a mottled gray paper envelope. maculata creates egg-shaped, paper nests up to 360 mm (14 in) in diameter and 580 mm (23 in) in length. 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.

Queen and worker wasps have similar morphologies. 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. It has a white or 'bald-faced' head, which is the source of its colloquial name. The bald-faced hornet is distinguished from other yellowjackets by its striking black-and-white coloring. Its black and white coloring differentiates it from its mostly black and yellow congenerics. maculata is part of the cosmopolitan family Vespidae, in the genus Dolichovespula. It was first described by Carl Linnaeus in his 1763 Centuria Insectorum. The bald-faced hornet gets its name from the characteristic white markings on its face, as the word 'bald' in English is derived from the word ' piebald'. Worker females can, therefore, lay eggs that develop into males. Males in this species are haploid and females are diploid. The bald-faced hornet is distributed throughout the United States and southern Canada, but is most common in the Southeastern United States. Workers aggressively defend their nest by repeatedly stinging invaders. It builds a characteristic large hanging paper nest up to 58 cm (23 in) in length. Colonies contain 400 to 700 workers, the largest recorded colony size in its genus, Dolichovespula. Technically a species of yellowjacket wasp, it is not one of the true hornets, which are in the genus Vespa. 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. Dolichovespula maculata is a species of wasp in the genus Dolichovespula and a member of the eusocial, cosmopolitan family Vespidae.

Black wasp with white stripes