Extension Educator, Horticulture
In autumn we head outside for tailgating and outdoor festivals. Some unwanted guests come all dressed up in black and yellow. Yellowjackets are in the bee and wasp family. The yellowjacket's ability to repeatedly sting makes them a considerable health threat. Yellowjackets alone are responsible for about one half of all human insect stings.
Yellowjackets are commonly confused with honeybees. They are the same size about ½ inch long, but yellowjackets are more brightly colored with definite yellow and black stripes and very little hair. Honeybees are more honey colored and covered with fuzzy hair.
Yellowjackets live in underground nests in old rodent burrows, in woodpile, piles of brush, compost piles or hollow trees. In late summer the yellowjacket nest may contain several thousand wasps. New nests are started each spring.
Yellowjackets are attracted to areas with sweet food such as picnic areas and ice-cream stands. Open cans of garbage or unclean garbage cans are the biggest yellowjacket attractants. Also areas of rotting fruit such as around apple trees can produce high populations of yellowjackets. Since yellowjackets often crawl into soda cans unnoticed, people are frequently stung on the lips.
Ways to avoid yellowjackets include not wearing perfumes or other scents including scented hair spray or deodorants. Avoid wearing brightly colored and patterned clothing. Don't go barefoot. Outdoors drink from cups with lids.
Avoid swatting or squishing yellowjackets. Squashing a yellowjacket releases a chemical that signals other wasps in the area to attack. The worst reaction is the chaotic sequence of flailing arms and the swatting of the offending yellowjacket. Just remember in the Tarzan movies the lion bait was the guy that went into the jungle screaming.
Yellowjackets will not bite or sting a person unless they or their nests are agitated by fast movements, stepped on or heaven forbid sat on. However they may land on your skin to take a drink of sweat or inspect a smell. Just be patient and they will fly away or lure them away with a bit of your food. If you can't be that patient, very gently brush them off with a piece of paper with slow deliberate movements. The same method should be used if a yellowjacket makes its way into your car.
Yellowjacket traps can be useful. Sometimes just putting a little meat or fruit in a dish far from your activities is enough to draw them away. However, keeping garbage cans clean and covered, keeping outdoor food areas clean and removing rotting fruit is still necessary to keep yellowjackets in check.
A yellowjacket nest around the home requires additional control measures. Remember bees and wasps are important pollinators so indiscriminant destruction of their nests should be avoided.
Yellowjackets like other wasps and bees are active during the day. Control measures should therefore be conducted at dusk or dawn without a flashlight. If you must use a flashlight, cover the lens with red plastic so they won't be attracted to the light.
Yellowjackets can be controlled with wasp and hornet sprays containing mint oil, permethrin, tetramethrin, or tralomethrin. Be sure to read and follow all label directions. Underground nests can be controlled with permethrin. Immediately after application shovel some soil down the hole and then run fast, run far.
Above ground nests can be dusted with cabaryl (Sevin) pesticide to coat the opening. Read and follow all label directions. The insecticide should not clog the nest. The dust can also be placed on a small piece of steel wool or cotton to surround the hole. As the yellowjackets go in and out they get the pesticide on their bodies. As they groom, they ingest the pesticide. Nests should be killed in about five days.