Wasps Management

PEST SOLUTION : WASP MANAGEMENT
Wasp Managment

Importance

Wasps are considered pests in the following situations:

In soft fruit production facilities.
In sugar warehouses, jam factories and sweet-smelling substances factories.
In beehives.

In the spring, they take away foraging worker bees.
Later in the year, they steal honey and carry off bee larvae and pupae.

In houses where food sources are available such as fallen fruits, spilled food materials, drink sources, soft drink cans and garbage.

Biology & Habits

During the late fall and early winter, as harsh weather approaches, newly matted/ fertilized queens seek protected habitats to spend the winter (over-wintering). Overwintering places differ depending on the species. However, overwintering locations are normally located under tree bark, woodpiles, in stumps and logs, and inside walls of structures. For example, the golden paper wasp, Polistes aurifer, is known to overwinter in wall void, crawl space, attic, chimney, basement, garage or window well of homes. In early spring, every queen will build a new nest. It will not use an old nest, but may build on the side of an old nest. The storage of sperm inside the female queen allows her to lay eggs without need to mate again with a male wasp. Initially, the queen lays about 10-20 eggs. These eggs will develop into sterile females or workers that take care of the colony (raising, feeding, cleaning, fixing, defending and construction). At this point, the queen's only job now is to lay more eggs. By the end of summer, when the colony is enlarged in size and number, males and new queens are produced in a large number. They fly out and mate. Males die soon after mating. The new-mated queens repeat the life cycle by seeking protected areas for over-wintering, while workers and the original founding queen do not survive the winter. Social wasp workers live for 12-22 days, and the average lifespan of queens is about one year.

Wasps are very important pollinators. They feed on pollen and nectar from a variety of flowers. This helps moving pollen from a flower to another, and thus pollinates various crops. Adult wasps feed on sweet materials such as honeydew, fruit and other sweet resources. They provide their larvae with necessary protein diets by feeding them on other invertebrates including spiders and insects. They also feed them on pieces of meat products.

Female wasps have stingers that they use to subdue and capture preys such as insects or spiders to use as food for their larvae. If handled, wasps may sting people to protect their nests. Unlike bees, wasps can sting more than once because they are able to pull out their stinger without injury to themselves. When they sting, they inject venomous fluid that may cause allergic reactions in people. People react differently to wasp stings. Some individuals develop normal reactions such as itchy, redness and swelling areas of the skin that resolve in a few hours. Other people may develop mild reactions to wasp stings including intense redness, swelling on both sides of two joints, itching and pain that all occurring within minutes. However, sensitive people develop sever reactions that lead to generalized swelling and itching, faintness, sweating, a pounding headache, stomach cramps or vomiting, a feeling of impending doom, a tight chest or choking sensation with swelling of the throat and in extreme cases anaphylactic shock with death resulting.

Habitats

Social wasps build nests of chewed up fibers or decaying woods mixed with saliva. The nests are usually found in sheltered areas outdoors in gardens, hedges, forest edges and other similar locations. Some species nest in the ground or at ground level in fallen logs and tree stumps. In urban settings, they can also nest under stairs, in fence posts, in brick walls, under eaves, under porches and in discarded mattresses, carpets or boxes.

Management

Prevention

Block queen’s entrances by sealing all cracks and crevices and apply wire screen in your windows.
Remove fallen fruits, spilled food materials, drink sources, soft drink cans and garbage.
Avoid scents and bright colors materials.
Keep your house, dumpster, garage, attic, etc. clean.

Physical Removal

To reduce risks to you and your family, contact your Pest Management Professional (PMP) to remove wasp nests in an accessible area to reduce foraging wasps.
Where wasps are common problems, use lure baited traps especially in the late fall and early spring for trapping queens.

Chemical Management

If needed, contact your PMP to apply an EPA registered fast knockdown residual insecticide (dust formulations are recommended or aerosol).
Treatment should be performed at night when temperatures have decreased, and when most of the foraging wasps are in the nest and less active.
Request product label & Material Safety Data Sheets (MSDS).
Follow precautionary measures provided by your PMP before and after treatment.

Precautionary Measures

Before treatment, wear protective clothing and other physical protection measures.
During the treatment, no people, food, or pets should be present in the area to be treated.