Bald face Hornet is a wasp of the cosmopolitan family Vespidae. Its colloquial names include the bald-faced hornet, bald hornet, white-faced hornet, white-tailed hornet, spruce wasp, black jacket, 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 centimeters (23 in) in length. Workers aggressively defend their nest by repeatedly stinging invaders.
Bald face Hornets are distributed throughout the United States and southern Canada but are most common in the southeastern United States. Males in this species are haploid and females are diploid. Worker females can, therefore, lay eggs which develop into males. Matricide might occur after sufficient workers have been raised and queen-destined eggs have been laid, in order to give workers a reproductive advantage.
Taxonomy and phylogenetics
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. It was first described by Linnaeus in 1763. It is in the genus Dolichovespula. Its black and white coloring differentiate it from its mostly black and yellow genus mates.
Baldfaced hornets are distinguished from other yellowjackets by their white and black coloring. It has a white or “baldfaced” head, which is the source of its colloquial namesake. These wasps also have three white stripes at the end of their bodies. They are notably larger than other species of Dolichovespula, as adults average about 19 millimeters (0.75 in) in length. Queen and worker wasps have similar morphologies. However, workers are covered by small hairs while the queen remains hairless. 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.
A Bald-faced Hornet creates egg-shaped, paper nests up to 360 millimeters (14 in) in diameter and 580 millimeters (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.
Inside the paper covering of a bald-faced hornet nest are several suspended combs containing chambers for larvae
Bald-faced hornets are omnivorous and are considered to be beneficial due to their predation of flies, caterpillars, and spiders. However, their aggressively defensive nature makes them a threat to humans who wander too close to a nest or when a nest is constructed too close to human habitation. They vigorously defend the nest, with workers stinging repeatedly, as is common among social bees and wasps. However, the baldfaced hornet has a unique defense in that it can squirt venom from the stinger into the eyes of vertebrate nest intruders. The venom causes immediate watering of the eyes and temporary blindness.