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Pest of the Month - Yellowjackets

The flying pests of summer

Yellowjacket wasps prey on other insects and scavenge on human food and garbage. Yellowjackets defend their nests, as do other social wasps and bees, but are more likely to sting if disturbed while foraging. Stings generally cause pain and short-term injury, but some people suffer severe allergic responses. Prevent injury by avoiding wasps and removing food sources. Trapping or nest treatment can reduce populations.

Make sure it’s a yellowjacket.

• Yellowjackets are 1/2 to 1 inch long with jagged, bright yellow and dark black stripes. Their narrow “waist” is barely visible. Unlike other common wasps, yellowjackets scavenge on food. They nest in holes in the ground, inside wall cavities, or in hanging nests enclosed in gray paper.
• Honeybees are less brightly striped than yellowjackets and are hairier. Usually they aren’t attracted to food (although sometimes to sweets) and are unlikely to sting unless trapped or stepped on. They usually nest inside of cavities in trees or houses.
• Paper wasps have long slender waists, build open paper nests under eaves, and are rarely aggressive.
• Mud daubers are dark-colored and thread-waisted; build small, hard mud nests; and rarely sting.

Keep your cool to avoid stings.

• If a wasp lands on you, don’t swat it or run. Wait for it to leave, or gently brush it away.
• Don’t disturb nests. Wasps flying from a hole in the ground or a building indicate a probable nest.

Remove attractive food sources.

• Keep foods, including pet food, covered or indoors.
• Cover soda cans outdoors so wasps don’t crawl in.
• Keep garbage in sealed cans and empty regularly.
• Pick up and dispose of ripe fruit.

Use traps to reduce yellowjackets locally.

• Yellow lure traps hung along the perimeter of a property can reduce foraging of some species around patios or picnic areas.
• Homemade traps using meat bait hung on a string just above soapy water may also be used.
• Place traps away from areas, such as picnic tables, where people congregate.

To protect yourself and your family, consider calling a professional if you find nests.

• Ask your Mosquito and Vector Control District if they treat nests, or locate a licensed pest control operator.
• If you choose to treat nests yourself, wear protective clothing on your body, hands, and head. Use an insecticide that shoots a long stream into the nest entrance.
• Nests might be far away and impossible to locate.
• Paper wasp nests shouldn’t require treatment unless they are near human passageways.

 

Courtesy of UC IPM Quick Tips