Yellow Jackets

Yellow Jackets

Yellow Jacket Scientific Name: Vespula squamosa

Yellow Jacket Facts

Picnicking just isn’t the same with these uninvited guests. An unsuspecting picnicker may find a surprise in his or her soda can—or within a peanut butter and jelly sandwich. Yellow jackets are often found wherever food is in abundance—be it around trash cans, at a ball park, or, yes, even at the quiet picnic in the park. The bad thing about yellow jackets is they do sting, and unfortunately the stings aren’t pleasant. Not only do they hurt, but they can be threatening if many yellow jacket stings occur at once or if the individual has an allergic reaction to the venom. Thankfully they usually don’t sting except in defense of their nest or when physically harmed.

Seventeen species of wasps exist in North America. The Western Yellow Jacket is the most common species in urban regions.

Yellow Jacket Identification

Yellow jackets are named for their uneven black and bright yellow stripes. They are about one-half to an inch long and have six legs. They have a waist most people wish for—a narrow one that’s hardly noticeable. They are big scavengers and hunt for their food—hence their frequent appearances at picnics and other outdoor events involving food.

Yellow Jacket Habitat

Yellow jackets find home in holes in the earth, in cracks in walls, or in nests that hang that are wrapped in gray paper. They typically build nests in rodent holes. Colonies are formed every spring by a female that’s able to reproduce. Based on the species, the colony can have a population anywhere from 1,500 to as large as 15,000.

Life Cycle of Yellow Jacket

The queen that starts the colony is one who has mated in the fall and overwintered. This overwintering has likely taken place beneath a log’s bark. Adults who are part of the first offspring take on all responsibilities other than laying eggs. The queen dedicates the rest of her life to laying eggs and for this reason never again departs from the nest. Female workers who are sterile occupy the colony for much of the season, and they are much smaller than the queen. Each worker has a specific chore—feeding larvae or nest constructing for example—though the task may change if needed.

Yellow Jackets and Humans

Yellow jackets are defensive of their nests and are likely to sting if they are encumbered while searching for food. Stings may cause pain and some injury, and some people may have a bad allergic response. Stings can be avoided by avoiding the yellow jackets and not giving them a reason to come close. In other words, remove food from outdoor areas.

Yellow jackets can sting over and over again, unlike bees. In fact, some estimates claim that almost 98 percent of all stings are incurred by yellow jackets. The best thing to do if a yellow jacket lands on you is to remain calm. It’s best not to swat it or run. The best options are either to wait for it to fly away or lightly brush it off of you. Yellow jacket nests should also not be disrupted.

Yellow Jacket Control

Avoiding yellow jackets is clearly the best approach to preventing bad encounters with them. It’s best to refrain from going anywhere near their nests. Yellow jackets flying in and out of one spot are most likely flying in and out of their home.

Food equals problems. When food is outdoors, it—including food and drinks for pets—should be covered. Soda cans or bottles should also be covered so the wasps don’t fly in. If it’s not possible to cover the food, it’s best to keep food items indoors. Garbage lids should be securely sealed. If yellow jackets sense a food source outside, they will remain in the area, searching even after the food has been sealed or moved.

If a wasp nest needs to be removed, it’s best to contact a professional for help. A Mosquito Control District can be contacted to see if they will treat a yellow jacket nest

. A professional pest control operator may also be contacted.

If attempting to treat a nest alone, here are some tips to remember:

  • Protective gear should be worn on the body, hands and head.
  • An insecticide can be used that shoots an long distance stream into the entrance of the nest.
  • Yellow lure traps can be hung around the outline of a yard to help reduce foraging.
  • Homemade traps can be made with meat bait hung on a string directly above soapy water.
  • It’s important to remember that traps should be kept away from patios or areas where people tend to gather.
  • Unless they are near areas where people walk, paper wasp nests likely don’t need to be treated.

Yellow Jacket Entomology

Cooperation and Competition

Yellow jacket workers feed their young a diet consisting of Workers progressively feed larvae a diet of carrion that’s fresh, chomped up flesh of insects and other arthropods. Yellow jackets feed on Lepidopterous larvae. In the fall, bigger cells are made for new queens. The larvae in these cells get more food than those in ordinary cells. The queen begins to lay unfertilized or male eggs either in the big or the small cells. After exiting the cells, the new queen yellow jackets mate and find home for the winter months. These will soon be the “founders” of the colonies in the coming spring. The veteran founder queen perishes, and the workers start to have erratic behavior until order within the colony ceases to exist. The remaining colony dies off with winter’s onset.

Relationship With Other Organisms

Yellow jacks play an important role in that they consume big amounts of other pests, including caterpillars and flies that may be harmful. They are also pollinators. Because of this, yellow jackets should be protected. It’s best, however, if their nests are away from humans.

Nest/Home Construction

Yellow jackets construct a paper nest from wood fibers and saliva. All nests are a group of horizontal combs protected by a paper envelope, with one hole for an entrance. If this hole isn’t big enough, the wasps will enlarge it by wetting the soil and digging. This same activity can sometimes create a wet area that may result in a hole in a wall or top of the nest. The nest has numerous levels of vertical cells.

The solitary queen constructs cells for the nest, and in addition she also initially finds food, lays eggs, feeds her young and defends from invaders.