Cicada

Common names: Cicada, Dogday Cicada, Dogday Locust, Harvestfly, Harvestman Cicada, Locust

Scientific name: Order Homoptera, family Cicadidae, many genera and species

Size: Adult—1" to 3"

Identification: The big insects that make all the noise in mid-summer. They have wide, blunt heads with big bulging eyes and clear, brittle wings. Empty nymphal skins can be seen attached to trees, shrubs, and buildings in the summer. Skin looks like a hollow Junebug skin.

Biology and life cycle: Males sing in a loud, sustained, shrill song in the spring through early summer. Nymphs have stout brown bodies with large front legs used as scoops. They feed on roots and molt until ready for the last molt. They dig out of the soil, climb a tree, and attach to tree bark or sometimes windows and door screens. Adults emerge during the final molt through a slit in the back, feed for a 5 or 6 weeks, mate, and then lay eggs in slits in tree branches. In two months the eggs hatch and the nymphs drop to the ground and burrow into the soil.

Cicada eggs remain in the twigs for 6 to 10 weeks before hatching. After the eggs hatch, the tiny ant-like first stage nymphs drop to the soil to borrow in 6 to 18 inches underground to feed for the next 2 or more years. Nymphs feed on the roots of many kinds of trees.

Some cicadas develop thirteen or seventeen years cycles, called annual cicadas and periodical cicadas. According to Korey Morgan of the US Forest Service Office of Communication

As the periodical cicadas take flight in awesome numbers; rumors and misunderstandings fly around along with them. Residents fear for their vegetable gardens, their yard trees, and their favorite parks and forests. For some, the insects are even evoking imagery of a biblical plague.

"People really shouldn't worry. Cicadas are not defoliating insects and have nothing to do with locusts," said Sandy Liebhold, research entomologist with the Forest Service's Northern Research Station in Morgantown, West Virginia. "They won't eat your plants, vegetables, or even the leaves of trees. They are emerging only to mate and lay eggs."

Even people familiar with annual cicadas are likely unaccustomed to their periodical relatives. Thousands of cicada species are commonplace across the temperate world. For residents of far flung cities such as Seoul, Rome, and New York City, their annual cacophony is a reminder of the dog days of summer.

Periodical cicadas, however, are unique to an area that spans from Texas to Massachusetts.

"There is nothing quite like the periodical cicada in existence anywhere else in the world," said Liebhold. "Most cicadas, in fact most insect species, complete a lifecycle in one year or less. Not so with periodical cicadas. A single generation lives for more than a decade underground and comes up every 13 or 17 years in extraordinary abundance."

Habitat: Any treed area, conifers and mixed woods. Also in shrubs.

Feeding habits: Nymphs feed on tree roots. Plant damage comes from the egg-laying slits in stems, which cause tip growth to die.

Economic importance: Cause little major plant damage. Most serious damage comes from the egg-laying slits in the bark of small branches.

Natural control: Cicada killers.

Organic control: We know of no effective techniques yet. There are never enough of them in any one place. Beneficial nematodes will help.

Insight: Wrongly called locusts. Females have no sound apparatus. Only males make the sound. They probably defend themselves with their high-pitched sound. The male, which is sometimes called the harvestfly, is responsible for the sad, sustained sound that fills the air on hot summer days. This sound is a mating call and also a means of protection, so loud it hurts the ears of some predators.

This map of periodical cicada broods in the US was produced for the US Forest Service in May 2013.
There are noisy years when the 17-year and 13-year cicadas emerge at the same time. Click on the
photo to pull up the full-sized PDF and publication information. 

For more information, read the US Forest Service article Cicadas stir up a ruckus by Korey Morgan in May, 2021.

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