Yellowjackets: Good Guys or Bad?

Sometimes it’s difficult to tell good from bad. Take the yellowjacket for example. When you hear yellowjacket, what’s the first thing that comes to mind? A buzzing, stinging insect ruining your outdoor meal or a treasured pollinator of many plants?

To be honest, a yellowjacket is both!

The most commonly found yellowjackets in our area is the Eastern yellowjacket (Vespula maculifrons). The Eastern yellowjacket is a wasp that is ½ to 5/8 of an inch long and is black and yellow striped. The body is curved under and is wider then the head. Yellowjackets do not have any “hairs” such as are found on honeybees and bumblebees.

Yellowjackets are generally ground nesters, however, in some situations, especially in urban areas, they will make their nest above ground such as in hollow walls and attics.

During the spring and summer, the colony population increases from the fertilized solitary queen, who survived the winter, to several thousand. The adult yellowjackets feed protein to the young wasps and larvae while they subsist on sugars. Foraging for food, the wasps cross-pollinate plants while seeking small insects and nectar. Yellowjackets provide a valuable service to humans by consuming numerous insects that eat ornamental and cultivated plants.

On the other hand . . .

Yellowjackets, drawn to cookouts, picnic areas and garbage cans for food, create a nuisance. Their sting, unfortunately, is especially painful. Unlike honeybees, which only sting once, wasps sting numerous times. Some people react severely to the venom and may have problems breathing or worse.

Here are some ways to reduce the possibility of inviting yellowjackets to your outdoor party:

  1. Don’t leave moist pet food outside during the summer. (Bird seed is fine, but not suet)
  2. Keep garbage cans washed. Securely cover all garbage cans and recycling containers. Rinse beer, wine, soft drink and ice cream containers.
  3. Keep garbage cans away from entertainment areas.
  4. If eating outdoors, cover all serving plates and drinking glasses/bottles to prevent yellowjackets from getting into food or drink. When yellowjackets are in the area, be sure to check your food and drink before consuming.
  5. Yellowjackets feed on aphids and scale on trees and shrubs. Therefore, spray for these pests in July and August, if needed.
  6. Repair dripping hoses and faucets as the puddles attract the wasps.
  7. Wasps enjoy rotting fruit. Harvest tree and cane fruits when ripe. Carefully pick up all fallen fruit (gloves are a good idea!).
  8. Wasps create a flight-path from the nest to food sources. Avoid this area. If this is not possible, consider removing the nest.

To help make your outdoor gatherings more pleasant and safer, we offer yellowjacket traps. Hang these around the perimeter of your yard if you plan to eat outside. Never hang these near the food area, as you will only increase the attraction to that area. Some traps are disposable and have the benefit of reducing the sting possibility. Others are “reusable” and must be emptied and refilled with bait. These increase the probability of being stung.

When necessary, the elimination of a nest should not be undertaken lightly. If it’s early in the season, and the nest is visible, a forceful water blast will break it apart. To reduce the chances of being stung, do this during the day while the workers are not home. Wasps return to the colony at dusk. Sometimes the workers will begin rebuilding in the same place. We offer pesticide sprays to kill wasps. If it’s later in the season, the aerial nest may be too large to eliminate safely.

Underground nests create a much bigger challenge. Because the entrance may be at an angle to the nest, flooding seldom works. Never try to burn a yellowjacket ground nest by pouring kerosene or other flammable liquid into the entrance and lighting it. In addition to many stings, injuries that are more serious may occur. This also pollutes the soil. If the flight pattern to the entrance creates a serious hardship or is close to a building, it is best to consult with an expert.

If the yellowjackets have built their colonies within your house walls or attic, it may also be necessary to contact a professional. Note: if yellowjackets are nesting in your home, do not plug the entrance/exit hole or they may chew the rest of the way into your house! Check with us for a professional referral or search “Pest Control” for your city on the Internet or in the yellow pages.