Sphecius Speciosus - Life Cycle and Habits

Life Cycle and Habits

Solitary wasps (such as the eastern cicada killer) are very different in their behavior from the social wasps such as hornets, yellowjackets, and paper wasps. Cicada killer females use their sting to paralyze their prey (cicadas) rather than to defend their nests; unlike most social wasps and bees, they do not attempt to sting unless handled roughly. Adults feed on flower nectar and other plant sap exudates.

Adults emerge in summer, typically beginning around late June or early July and die off in September or October. They are present in a given area for 60 to 75 days, usually until mid-September. The large females are commonly seen skimming around lawns seeking good sites to dig burrows and searching for cicadas in trees and taller shrubs.

The males are more often seen in groups, vigorously challenging one another for position on the breeding aggregation from which they emerged, and generally investigate anything that moves or flies near them. It is not unusual to see two or three male wasps locked together in apparent midair combat, the aggregate adopting an erratic flight path until one of the wasps breaks away. The male wasp's aggressive behavior is similar to that of another robust insect of the area, the male carpenter bee. In both cases, while the males' vigorous territorial defense can be frightening and intimidating to human passersby, the males pose no danger whatsoever. They will only grapple with other insects, and cannot sting.

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 typical burrow is 25–50 centimetres (10–20 in) deep and about 1.5 cm (0.59 in) wide. In digging a burrow, the female dislodges the soil with her jaws and, using her hind legs, pushes loose soil behind her as she backs out of the burrow. Her hind legs 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. After paralyzing a cicada, the female wasp holds it upside down beneath her 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 one or more cicadas in her nest cell, the female deposits an egg on a cicada and closes the cell with dirt. Male eggs are laid on a single cicada but female eggs are given two or sometimes three cicadas; this is because the female wasp is twice as large as the male and must have more food. New nest cells are dug as necessary off of the main burrow tunnel and a single burrow may eventually have 10 or more nest 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.

This wasp is frequently attacked by the parasitic "velvet ant" wasp, Dasymutilla occidentalis, also known as the "cow-killer" wasp. It lays an egg in the nest cell of the cicada killer, and when the cicada killer larva pupates, the parasitoid larva consumes the pupa.