Late summer is the time of year when yellowjacket wasps (commonly called "bees") become most noticeable. Yellowjackets are the size and shape of honey bees (about 1/2 inch long) and shiny black with bright yellow markings. Honey bees are golden brown and fuzzy.
Yellowjacket wasps are social insects. Each colony starts with a single queen in May. The number of wasps in the nest remains very small through the early part of the summer, but reaches a peak population of up to 5,000 wasps per nest by September.
Yellowjackets build paper nests either in the ground, in a log or landscape timber, or inside a building wall or attic. Nest openings are discovered by the activity of workers hovering back and forth at the small hole. The workers travel up to a few hundred yards from the nest while looking for food. In the early summer, yellowjackets eat caterpillars and other "meat" items. In the fall, they prefer sweets such as pop and candy residue in garbage cans.
If a nest is located where it is out of the way and not likely to be disturbed, it is best left alone. If, however, a nest is located in a "high traffic" area such as along walks or near doorways, control is justified to reduce the threat of being stung.
Nests in walls or in the ground can be destroyed by placing an insecticide dust (e.g., Boric acid, Sevin or permethrin) in the nest entrance during the night. Wear protective clothing and approach the nest with caution. Do not shine your flashlight directly into the nest opening.
A hand duster or similar application device makes it possible to dispense several puffs of the dust into the nest opening. Use a dry, empty liquid detergent bottle filled with no more than 2 tablespoons of dust and shaken before dispensing in lieu of a commercial duster. Control will usually be achieved within a few days. Retreat after 2 or 3 days if necessary. Do not plug a nest opening in a house wall until you are sure all activity within the nest has stopped.
The "wasp and hornet" aerosol sprays that can shoot the insecticide several feet may or may not provide effective control of yellowjacket nests inside walls, depending on how far the nest is from the nest opening.
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