Yellow jackets are aggressive when threatened. Unlike a honeybee, which stings only once, a yellow jacket can sting repeatedly. The sting can be life-threatening to those who are allergic to it. A native of Europe, the German yellow jacket reached Wisconsin in 1979. Its arrival sparked a sharp increase in emergency room treatments for stings.
Foragers return to their nest with food, which they feed to adult and larval wasps.
Jeanne and his students at the College of Agricultural and Life Sciences have been studying the compounds in foods that German yellow jackets find attractive and how the wasps locate food. Jeanne hopes the results will lead to better methods to control the pest. The Wisconsin entomologists showed that foraging German yellow jackets can recruit other workers from their nest to a food source, although they are not nearly as good as bees are at recruiting nest mates. Although there are commercial wasp traps that drown the pests, they are unlikely to control German yellow jackets, according to Jeanne. Killing even a thousand yellow jackets may not make much of a difference.