Springtime is close at hand and along with spring comes those dreadful yellowjackets. These yellow- and black-banded insects win first prize, by far, for the top “stinging” pest in Colorado. By understanding them a bit more it may help us to avoid these troublesome wasps and enjoy a sting-free season.
The term “yellowjacket” refers to a number of different species of wasps in the genera Vespula and Dolichovespula (family Vespidae). Included in this group of ground-nesting species are the western yellowjacket, V. pensylvanica, which is the most commonly encountered species in our diocese. They are sometimes called “meat bees” because of their appetite for protein.
Identification. Being able to identify the difference between a bee and a wasp is important. For general identification the honey bee, bumble bee and leaf cutter bees are hairy, stout bodied with muted colors of black, brown, yellow, orange and gray and commonly have pollen on their bodies. Hornets, yellowjackets and paper wasps are not hairy, have elongated bodies and brighter coloring of black, yellow, orange and creamy white. Bees are beneficial pollinators.
Wasps are beneficial insect predators. Bees and wasps are usually non-aggressive unless trapped (stepped on) or their nest is disturbed. Solitary bees as well as honey bees have no interest in human food. On the other hand, yellowjackets are scavengers and thrive on sugary drinks, sweet food and meat. Yellowjackets typically nest underground using existing hollows. Nests might be found in dark, enclosed areas, such as crawl spaces, under low lying decks or in garden sheds. Honey bees live in an above ground hive or in a tree. Solitary bees are seldom noticed. According to Colorado State University 90% of the bees in Colorado are solitary types, including leafcutter, digger, sweat and carpenter bees. They nest in hollow twigs, or any other opening about the diameter of a pencil. They also utilize cracks and hollow tubes of patio furniture.
Control. Western yellowjackets are attracted to the chemical hepytl butyrate, which makes them susceptible to early control with a wasp trap. These reusable traps can be purchased at most local hardware and garden stores. The great news is that no other bees or wasps are attracted to the yellowjacket baited wasp trap. This trap should be placed in April when the queen is foraging for nesting material and protein. Store-bought traps require a refill of the chemical attractant every 4-10 weeks. They are relatively inexpensive (around $10 for the trap and $4 for the refill attractant) and do a decent job.
There are many do-it-yourself traps made from plastic soda/water bottles that produce good results. Dr. Peter Landolt, a USDA entomologist in Wapato, Washington, studies the chemical ecology of insects, and has developed do-it-yourself traps to attract food-eating social wasps. The key is first determining the problem wasp species, and then selecting an appropriate trap. His research has found that yellowjackets are attracted to meat baits. A simple trap can be made by cutting the top from a plastic soda bottle and inverting it (without the lid) into the bottom “cup.” Punch a hole on each side of the cup and hang the trap using wire or twine. Hang a piece of meat just below the funnel-shaped top and fill the cup with water plus 1 tsp of dish detergent. Position the meat so that the wasp will fall into the soapy water when it attempts to fly away after cutting off a piece. Landolt warns against adding insecticides because the sweet traps could attract and harm honeybees.
“Anger is as a stone cast into a wasp’s nest.” — Pope Paul VI.
(Kerry Peetz is a master gardener and member of Sacred Heart Parish in Colorado Springs.) (Photo by Kerry Peetz)