Cicada Killer Wasp
Adult Eastern cicada killer wasps are large, 2/3" to 2 inches (1.5 to 5 cm) long, robust wasps with hairy, reddish and black areas on the thorax (middle part), and are black to reddish brown marked with light yellow stripes on the abdominal (rear) segments. The wings are brownish. The females are somewhat larger than the males, and both are among the largest wasps seen in the Midwest, their unusual size giving them a uniquely fearsome appearance.
Cicada killer females use their sting to paralyze their prey (cicadas) rather than to defend their nests. They are present in a given area for 60 to 75 days, until mid-September. The large females are commonly seen in mid-to-late summer skimming around lawns seeking good sites to dig burrows and searching shrubs and trees for cicadas.
This ground-burrowing wasp may be found in well-drained, sandy soils to loose clay in bare or grass-covered banks, berms and hills as well as next to raised sidewalks, driveways and patio slabs. Females may share a burrow, digging their own nest cells off the main tunnel. A burrow is 6 - 10 in. (15 to 25 cm) deep and about 1.5 in. (3 cm) wide. The female dislodges the soil with her jaws and pushes loose soil behind her as she backs out of the burrow using her hind legs, which are equipped with special spines that help her push the dirt behind her. The excess soil pushed out of the burrow forms a mound with a trench through it at the burrow entrance. Cicada killers may nest in planters, window boxes, flower beds or under shrubs, ground cover, etc. Nests often are made in the full sun where vegetation is sparse.
After digging a nest chamber in the burrow, female cicada killers capture cicadas, paralyzing them with a sting; the cicadas then serve as food to rear their young. After paralyzing a cicada, the female wasp straddles it and takes off toward her burrow; this return flight to the burrow is difficult for the wasp because the cicada is often more than twice her weight. After putting the cicada in the nest cell, the female deposits an egg on the cicada and closes the cell with dirt. New nest cells are dug as necessary off the main burrow tunnel and a single burrow may eventually have 10 to 20 cells. The egg hatches in one or two days, and the cicadas serve as food for the grub. The larvae complete their development in about 2 weeks. Overwintering occurs as a mature larva within an earth-coated cocoon. Pupation occurs in the nest cell in the spring and lasts 25 to 30 days. There is only one generation per year and no adults overwinter.
Adults feed on flower nectar and other plant sap exudates. Adults emerge in summer, typically beginning around late June or early July and continuing throughout the summer months.
What you can do: Usually it is not necessary to control cicada killer wasps unless their presence is a nuisance. Sometimes these wasps can be troublesome in high traffic home and commercial areas such as berms around swimming pools, near planters at door entrances, flower beds, golf course greens and tees, and other unwanted areas.
Sometimes they may fly erratically near people, causing fear. Males may actually defend their territory by dive bombing people's heads and shoulders!
Males aggressively defend their perching areas on nesting sites against rival males but they have no sting. Although they appear to attack anything which moves near their territories, male cicada killers are actually investigating anything which might be a female cicada killer ready to mate. Such close inspection appears to many people to be an attack, but male and female cicada killers don't land on people and attempt to sting.
If handled roughly females will sting, and males will jab with a sharp spine on the tip of their abdomen. Both sexes are well equipped to bite, as they have large jaws; however, they don't appear to grasp human skin and bite. They are non-aggressive towards humans and usually fly away when swatted at, instead of attacking. Cicada killers exert a natural control on cicada populations and thus may directly benefit the deciduous trees upon which their cicada prey feed.
Wasps are generally beneficial and a nest in an out of the way location where it is not likely to be disturbed should be left alone. If, however, a nest is located where problems could arise, such as under a deck or near an often used door, treatment by a Peoria Pest Eliminators service technician is justified. Ground nests of cicada killers and other digger wasps can be treated by the technician placing an insecticide dust in and around the nest entrance. The dust particles will adhere to the wasps as they come and go from the nest, thereby killing the wasps. For extensive infestations, additional treatment strategies may need to be implemented.