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.
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DiurnalDiurnal animals are active during the daytime, with a period of sleeping or other inactivity at night. The timing of activity by an animal depends ...
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TerrestrialTerrestrial animals are animals that live predominantly or entirely on land (e.g., cats, ants, snails), as compared with aquatic animals, which liv...
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OviparousOviparous animals are female animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive...
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starts withThe bald-faced hornet is distinguished from other yellowjackets by its striking black-and-white coloring. It has a white or "bald-faced" 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.
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. It is most common in the Southeastern United States.
D. maculata is found in forested areas and in vegetation in urban areas. Nests are generally located in trees and bushes, but occasionally are found under rock overhangs or the sides of buildings. 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.
Bald-faced hornets are omnivorous, and considered to be beneficial due to their predation of flies, caterpillars, and spiders. 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. They vigorously defend the nest, with workers stinging repeatedly, as is common among social bees and wasps. 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. The venom causes immediate watering of the eyes and temporary blindness.
Diet in D. maculata varies depending on an individual's life cycle stage and geographic location. Adult yellowjackets, like true hornets, are carnivorous, and prey upon several insect types. They have been observed consuming meat, spiders, fruit, and insects. Adults also drink flower nectar, which they feed to their larvae.
Each spring, queens that matured and were fertilized at the end of the previous season begin new colonies. A queen selects a location for her nest, begins building it, lays a first batch of eggs, and feeds this first group of larvae. These become workers and assume the chore of expanding the nest. They chew up wood, which mixes with a starch in their saliva. They then spread it around with their mandibles and legs, and it dries into a papery structure. The workers guard the nest and feed on nectar, tree sap and fruit pulp (particularly that of apples). They also prey on insects and other arthropods, chewing them up and feeding them to the larvae. They have been known to scavenge raw meat. In late summer and early fall, the queen begins to lay eggs that become drones and new queens. After pupation, these fertile males and females fly off to mate. Fertilized queens then overwinter and start new colonies during the next year. Males and workers die in the end of the cycle. The old queen, if not killed by workers, dies with them around mid-autumn.
