Arkansas Nature Trivia

Cicadas: Fun for Children, Omens of War for Politicians

By Renn Tumlison

Pictured here is a large insect called a cicada, a true bug known to many people as a locust (real locusts such as in "plagues of locusts" are grasshopper-like insects). Eggs laid under the bark of trees hatch, then larvae fall to the ground and enter the soil where they use piercing mouthparts to feed on sap from the roots of trees. After development underground, larvae come to the surface to metamorphose into adults, leaving holes about 1/2 inch wide that are commonly seen in late summer. They climb up trees or whatever is available near their exit holes, latch on with the claws at the ends of their feet, and break free of their skins to emerge as adult insects. 


Children often collect the shed skins, technically called exuvia, to hang wherever they please. Close observation of an exuvium reveals fine details of the shape of the insect, and a crack along the thorax (the back) from which the adult has emerged (see photo). The adult stage first frees itself from the skin, then waits for the wings to grow. When the wings are firm, the cicada flies into the trees and begins making the characteristic calls usually heard in August. Because these insects appear annually in the heat of late summer, they sometimes are called "dog-day" cicadas. 

A particular brood of a smaller species called the periodical cicada appears here only once every 13 years--May and June, instead of August. It emerges in great numbers and makes an incredible noise. An article in the Arkansas Gazette and Democrat reported them on May 25, 1855, with a note that some people believed them to be an omen of war because "they have red eyes, and the letter W (for war) on their wings." Brood XX of the periodical cicada appeared here in 1998, so brood XXI is due to appear in 2011.

Large insects such as the cicada could provide a good source of nutrition to predators able to take them. Some birds can feed on cicadas, and even the copperhead snake is known to climb trees in search of a meal of cicadas, sometimes becoming engorged on a large number of them.

There is a special predatory insect so focused on cicadas that the prey is its namesake--the cicada killer. The cicada killer has a background color of black or rusty tones with yellow markings across the black abdomen. This predator is a large wasp up to about 1.5 to 2 inches long and of the family Sphecidae--a family separate from that of paper wasps and hornets. And no surprise, it appears in late summer at about the same time as the cicadas emerge from the ground.

Female cicada killers average about twice the size of males, and only females have stingers. To be able to sting a hard-bodied insect like a cicada, the stinger would need to be strong and large. The stinger is impressive (see right photo) and has the reputation of causing great pain in humans, although the insect seldom attempts to sting people unless provoked.

The cicada killer can catch a cicada in flight, but usually it will be seen cruising fairly slowly over the ground in search of its prey. It nests in burrows in well drained soil, and provides the larvae in the nest with cicadas that it has paralyzed with a sting. It is better to paralyze than to kill, because killed cicadas would become moldy. The cicada then is used as food by larval cicada killers. The larva develops rapidly and overwinters within a cocoon, then emerges as an adult to start the cycle over.