Wasps (and Hornets)

The most commonly encountered are bald-faced hornets, yellowjackets, paper wasps and mud daubers. The bald-faced hornet, yellowjackets and paperwasps are social insects and build nests of a paper like material. Mud daubers are solitary and build nests of mud often plastered among rafters in attics or on the sides of buildings.

Hornets Bald-faced hornets (Dolichovespula maculata)are relatively large, black and usually have white markings on the front of their heads. This type of hornet tends to nest in trees but nests can also be attached to buildings. By the end of the summer their nests can be larger than a basketball.

Yellowjackets (Vespula spp.) are small, about 10 mm in length, bright yellow and black and appear hairless. Most will build nests underground but they will also nest in wall voids, attics or crawlspaces using an available hole or crack on the exterior. Yellowjackets are often considered the most dangerous of the bees and wasps as they are in frequent conflict with people, they contain hundreds of individuals, are very protective of their nests, and can be unpredictable in their response to people nearby.

Mud daubers (Sceliphron caementarium) are easily distinguished from other wasps and hornets as they have very long legs and a long thin "waist". While they have the ability to sting, they are not aggressive and generally only sting if handled

Paper wasps (Polistes spp.) are large (25mm), slender wasps with long legs and a distinct, slender waist. Most are brown or darker, with large patches of yellow or red. Their paper nests hang like an open umbrella from a stalk called a pedicel with the cells visible from below. They are usually in protected areas, such as under eaves, in attics, or under tree branches or vines. The populations vary between 15 to 200 individuals and they are generally not aggressive.

Control

With the exception of honeybees, the treatment for the different types of wasps is generally the same. In all cases, the nest must be located for proper treatment. A nest located in a wall or in the ground can usually be identified by observing wasps flying in and out of a hole or a crack. Never plug or seal up this hole before a treatment.

Treatment usually consists of treating the nest or entry point with a liquid or dust insecticide and/or removing the nest, if possible.
To reduce local populations of wasps in your yard or patio area, a non-toxic trapping program can be initiated.
Honeybees are highly beneficial and should be collected by a beekeeper.