By: Don Meehan

Believe it or not the Yellowjacket, and its relative the paper wasp, are good insects. Yes, I know it is hard to believe when they are buzzing around your head as you work in the yard or invade your picnic site as you sit down to eat. The good they do for our environment is in the kinds of things they consume for food. This is mostly in the form of other insects like house flies, blow flies and many other insects which ordinarily damage shade trees and crops.

We do not like to recommend controlling yellowjackets and wasps unless they pose a serious threat from their stings to family members. People who suffer allergic reactions to bee stings will want to consider removal of nests (by someone else) since yellowjackets and wasps have the ability to give multiple stings.

It is worth pointing out that Yellowjackets often are confused with honey bees. This confusion is unfortunate since honey bees are vital to pollination and honey production. To distinguish between the two is often difficult as they are buzzing around you. Honey bees are more compact and tend to be more orange and black. Yellowjackets are either bright yellow and black or white and black. Their markings are more vividly defined. Honey bees give up their life to sting someone. Their stingers are barbed and will not come out once injected into a victim.

The life cycle of the Yellowjacket operates in this fashion. At the beginning of spring there are only fertilized queens present. There are no workers at this point to help the queen. She will build a small nest with a very limited number of cells in it. Then she lays eggs in the nest cells and nurses them for about 20 days. When these hatch out they are workers and the queen stops nursing and spends all her time in the nest laying.

As the summer months appear the nest increases in size and may reach a population size of 4,000 workers. August and September are the peak months. At this time reproductive cells are formed and new males and queens are produced. As males and queens emerge mating takes place. Shortly thereafter the males all die and the queens, which have been inseminated, will seek over-wintering sites. Over-wintering sites are many and often include locations inside homes.

The nests built by Yellowjackets in the Pacific Northwest can vary between two major types. There are those built below ground in mouse burrows or similar sites, including inside walls of houses and other buildings, and there are those built as aerial nests in trees, sheds and under eaves of houses. All nests are completely enclosed unless made by paper wasps, which leave the cells in the next exposed. Nests used this year will not be used again next year. Usually nests will disintegrate over the winter.

There are a number of ways to control Yellowjackets, most use a chemical means. Once again, it is my recommendation that you not control them unless they pose a substantial danger to you.

Should you decide to control them there are some risks involved. The biggest risk of course is that of being stung. This can be minimized by doing chemical treatments during the very early morning when the nests are completely occupied and the Yellowjackets are sluggish from being cool. The other way is to use traps, but it must be kept in mind that this method is slower and does not solve the problem immediately.

For chemical treatments it is recommended that aerosols designed to propel a stream of insecticide 20 to 30 feet be used. This keeps you at a distance from the nest. It is also recommended that heavy clothing be worn which also protects your face and head. There are many other precautions which should be considered. These are listed in the WSU Extension publication called, "YELLOWJACKETS AND PAPER WASPS". It also provides specific details on trapping and chemical approaches to controlling. It can be obtained from our office by simply calling. We will be glad to mail it to you.

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