Baldfaced Hornets
Order:
Hymenoptera
Family: Vespidae
Scientific Name: Dolichovespula maculata L.
The baldfaced “hornet”
is taxonomically a black-and-white yellow jacket.
Vespid wasps, members of the family Vespidae, are capable of stinging
when threatened. Representatives
of Dolichovespula spp. can be found throughout North America, inhabiting
self-constructed paper nests usually attached to trees, shrubs or structures.
Biology and Habits
Like most social insects, the baldfaced hornet creates and maintains an organized colony. A single, inseminated queen initiates nest building in the spring after her emergence from a protective overwintering location. The initial construction of the nest includes a funnel-shape extension from the paper nest. The foundress queen tends to her first brood which later develops into foraging workers. The adult workers tend to the queen and the developing young while enlarging the paper nest and enclosing the original queen nest.
The exposed aerial nest is constructed from dead-wood fibers that hornets convert into laminar sheets. The sheets are often scalloped in texture. Characteristically, the nest is gray in color, and the entrance hole is located on the end closest to the ground. Nests are used for one season only.
Adult workers collect food for the developing colony. They capture live prey such as flies and caterpillars. The food is taken back to the colony and fed to the queen and the developing brood. Toward the end of the season, reproductives are reared by the colony. These reproductives mate, and the life cycle continues as the inseminated queen successfully overwinters and beings constructing a nest and laying eggs in the early spring.
In the eastern United States,
the duration between colony initiation to dissolution ranges from 15 to
23 weeks. Most colonies consist of less than 100 members, but others
can have up to 800 individuals.
Only queens overwinter, while the remaining colony members perish.
Control
Since these insects are aggressive and can sting anything that threatens their nest, use caution. Bee suits, gloves, eye gear, and hats must be completely sealed in order to provide protection from stings.
Look for suitable nesting sites. Threes, shrubs and exposed areas of buildings are attractive to foundress queens. If the nest is high off the ground, use a ladder or a pole.
A wide variety of products are labeled for stinging insets, including dusts, aerosols and liquid formulations. Avoid wind drift of any formulation and apply the pesticide as directed by the label.
In the past, control suggestions have encouraged insecticidal applications at night to ensure that most members of the colony are present and not foraging in the fields. However, daytime treatments are successful when additional insecticides are applied to the exterior of the nest to control any returning hornets. In either case, treatment includes the introduction of insecticides into the nest entrance.
If treatment is rendered at night, a flashlight or spotlight may be needed to locate the entrance to the nest. Do no leave the light on for long periods of time since it will attract the workers.
Although nests are not
reoccupied the following spring by new queens, the removal of the nest
whenever possible completes the professional job.
(Courtesy of the National Pest Control Association.)