TechNotes Sept. 18: Yellow Jackets, Soil Temperatures

Yellow Jacket or Paper Wasp?

Drinking a soda outside can be a real nuisance now that yellow jacket populations are on the increase. The yellow jacket is about 0.5 inch long and has alternating yellow and black bands on the abdomen. The yellow jacket is often times confused with honey bees. The honey bee is slightly larger than the yellow jacket and is covered with hair. The stinger on the yellow jacket is smooth and can be used multiple times, where the stinger on the honey bee is barbed and only used once. 

Yellow jackets are meat-eaters usually feast on caterpillars and flies early in the year. During late summer, their appetites switch from the high protein diet of insects to a carbohydrate diet. Thus, the appearance of yellow jackets at this time of the year around trash bins, picnic baskets, and open soda cans. Yellow jackets attack with little provocation. They appear to be attracted to people wearing dark cloths or intense floral patterns, musked-based perfumes, and bad breath (I guess it pays to brush your teeth.) 

Fortunately, yellow jackets do not overwinter as adults, so as cooler temperatures arrive this insect will become more lethargic. If a nest is near a home and control is desired, apply a labeled insecticide at night. Yellow jackets do not come out at night and control is best done at this time.

Paper wasps are sometimes confused with the yellow jacket. The common paper wasp is about 1-inch long, slender, long legs and reddish –orange to black color. Paper wasps nest in window sills, along eaves where they are protected from rain.  The nests are small honeycomb structures where the eggs are deposited and then the workers hatch and pupate.  At this time of the year most of the nests are empty. 

Soil Temperature Map