Periodical Cicadas
Noisy Invaders Return to Southwest Ohio in 2008
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| Brood X emergence will occur within the counties shown above. |
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| Cicada Oviposition Damage |
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| Adult Cicada. Click on image for a larger view. |
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| “Flagging” or breakage from slits |
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 Additional Information |
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Three species of periodical cicadas (genus Magicicada), will appear in parts of west central Ohio during the Brood XIV emergence in the spring of 2008. This brood was last seen in 1991.
Periodical cicadas are often called 17 year locusts. This is a misnomer, since true locusts are grasshoppers, not cicadas. Based on the year of adult emergence, cicadas are grouped into broods with each appearing during a different year. Due to staggered development, adults appear somewhere almost every year and since some brood territories overlap, a few areas may experience more than one emergence during a 17 year period.
Adult periodical cicadas have red eyes and dark bodies and measure slightly over 1 1/2 inches long. They do not bite or sting. Adults live about four to six weeks during which their sole purpose is to mate and lay eggs. Cicada “songs” will be heard from early morning to late evening as long as adults are present. Males are responsible for the droning noise as they call for mates. Periodical cicadas should not be confused with dog day cicadas which are larger in size, mostly green with black eyes, and appear each August in small numbers.“Flagging” or breakage from slits
Adult cicadas do not feed. Damage to deciduous trees (especially oak, apple, dogwood, and hickory) occurs when the female cicada cuts two parallel slits in small (pencil-sized) twigs where she lays 24 - 48 eggs. Sometimes a continuous slit 2 - 3 inches long is formed as she moves up a twig, repeating this process. The slits cause browning, breakage, and scarring on affected branches. The eggs hatch in six weeks and young cicadas, or nymphs, fall to the ground where they burrow into the soil and spend the next 17 years feeding on small roots. At the end of this time, usually in May and early June, nymphs crawl out of the soil and climb up tree trunks or other vertical objects where they shed their nymphal skin and emerge as adults.
Cicadas will not significantly affect most large, healthy trees. Small trees, however, can be more seriously damaged. Property owners and managers can reduce damage to smaller trees by pruning them lightly or not at all the season before emergence. Damaged twigs may be pruned out following cicada activity. Small shade and ornamental trees can also be protected by covering them with cheesecloth, finely woven netting, or tobacco shade cloth.
This physically prevents females from laying eggs in the twigs. In heavily infested areas, planting new deciduous trees and shrubs can be delayed until the fall or spring following cicada emergence to avoid potential damage. Trees that cannot be protected by some other means can be sprayed with a contact insecticide. Chemical control is difficult and not 100% effective due to the large number of cicadas present, their staggered emergence, and the relatively slow action of some pesticides. Caution should be used if spraying trees in flower because honey bees and other pollinators could be killed. Contact your local extension agent for insecticide recommendations and follow all label directions carefully.
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