For the Blog from Dr. Donald Lewis
The annual cicadas have been buzzing in the trees for the past week, and right on schedule, and right behind them, come the cicada killer wasps.
Cicada killer wasps are 2-inches long with black and yellow marking and orange wings. Their size makes them look and scary but they are not a threat to people and pets. But still people want to kill them because of their size.
Cicada killers are a solitary wasp. There is no colony as there is with honey bees, bumble bees and yellowjackets. Each female wasp works alone to dig a burrow and provision in with paralyzed cicadas that become the food source for her offspring. Solitary wasps are not aggressive and they can be tolerated, though most people choose not to!
The wasps that are randomly flying back and forth over an area are the male wasps defending their territory. Only female wasps and bees can sting. The males are harmless and the females are too busy working to pay any attention to you.
Cicada killer wasp tunnels may be 12 to 24 inches deep in the ground. Burrows are usually in bare soil and at an edge. The transitions between sand traps and turfgrass or between flower beds and turfgrass are favorite spots! There is only one generation per year and populations vary greatly from place to place and from year to year.
When cicada killer wasps cannot be tolerated, control is usually accomplished by putting insecticide dust into the nest opening at night. Liquid sprays applied to burrows do not work well because they soak into the soil. Dusts or powdered insecticides work better.
Read more in our online article at https://hortnews.extension.iastate.edu/cicada-killer-and-other-digger-wasps
Donald R. Lewis
Department of Entomology
Iowa State University
Ames IA 50011