|scientific name Vespula maculata |
common name Bald-faced Hornet
Open boreal forest, forest edges and prairies. Urban zones as gardens, parkland, meadows and houses.
Colonies are annual and short lived. Queens choose the nest in May. The colony decline in early October.
This species is black with white or ivory markings, the body is stout and the wings are smoky. In average the queen size 19 mm, males 14 mm and workers 13 mm (VanDyk 2003). Head: oculo-malar space is large more than half as long as the penultimate antennal segment; with ivory or white pattern on most of the face; black clypeal mark extending from dorsal margin ventrally. Mesosoma: pronotal carina always ivory or white; metanotum sometimes lacking pair of ivory or white spots; lower half of the sides of the pronotum and propodeum transversely striate; hind tibia largely or completely black marked with pale on outer surface. Metasoma: Metasomal terga 1 to 3 entirely black and terga 4 to 6 with white or ivory stripes; male aedeagus bifurcated distally.Sexual dimorphism: Males have long antennae 13 segments, workers and queen (females) antennae have12 segments (Buck et al. 2008, Miller 1961).
The Bald-faced Hornet is a social species with large annual colonies. Nest mostly are aerial, usually higher above the ground more than 20 cm. Nest are built in vegetation, on rocks, houses or wood structures, occasionally, nest may be subterranean or in hollow trees. It resembles grayish paper and its shape is like a big basketball, the nest is suspended in leaves, branches or other structures. The queen utilize chewing cellulose to build a paper nest with several cells, she deposits one egg in each cell, she nurse the larvae with nectar, insects and spiders, 30 days later the first workers emerges, the queen doesn’t leave the nest again and her function is egg laid. The mature colony is big; it holds 100-400 maximum 650 workers. The workers search food and fibers, help with the colony thermoregulation, care the larvae, clean the cells, feed the queen, the larvae and the males, they exhibit trophallaxis, mauling and ovoposition behavior, and also they protect the colony, 20 -75 Bald-faced Hornet are involved in defense of the nest and they can sting. In late September the larger reproductive cells for queens and males are reared. Finally, the colony declines in early October and all the members of the parental colony die. The old nest is taken by birds that look for larvae and pupae. At the end to the fall the new queens and males leave the nest and mate. Only inseminated queens hibernate and survive the winter, they burrow into a hollow old tree to survive the winter (Akre et al. 1981).
This species is common and this is not reported in vulnerability status.
Bald-faced Hornets are predators and they attack only live prey. They are mostly predators of spiders, harvestmen, hemipterans, spittle bugs, house flies, sawflies larvae, caterpillars, beetles, other yellowjackets species and grasshoppers. The adults carry their prey or part of them to the nest to feed their larval states. They sometimes feed of flower nectar or sweet substances (Akre et al. 1981, VanDyk 2003).
This Neartic species is widely distributed from Canada to United Sates. In Canada this species is present in all states and territories excluding Nunavut. In United States the species is present in Colorado, Illinois, Indiana, Massachusetts, Michigan, New Jersey, North Dakota, Oregon, Pennsylvania, Texas, Utah and Wisconsin (Buck et al. 2008, Miller 1961).
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