Wednesday, May 4, 2011

13-Year Cicada Expected To Make An Appearance

By Xing Ping Hu, Extension Specialist - Entomology & Plant Pathology

It has been 13 years since Alabama experienced the swarm of the cicadas in Alabama.  The last time the 13-year periodical cicada made a spectacular appearance was in early May 1998.  Alabama recorded having 2 cicada broods: XIX and XXIII. Broods are various populations designated by Roman numerals so scientists can refer.  Based on the records of the past results at Alabama Agricultural Experiment Station, the periodical cicada that will emerge this year is known as Brood XIX.  Brood XIX is the primary and biggest brood that we have in Alabama, which is a southeastern brood that ranges west into Louisiana and north into Illinois and southern Iowa. Brood XXIII primarily lives west of Alabama.  Cicada brood XIX is often referred to as 13-year “locus”, because the adult cicadas mass emerge from ground, precisely on schedule, every 13 years by millions.  The cicadas emerge at nights in later April or early May, and only live about 5-6 weeks. You may see numerous nymph skins on tree trunk, twig, and leaf.  They prefer to lay eggs in branches about the size of a pencil. Females cut into the underside of the branch and lay their eggs in it. The egg-loaded branches often wilt and fall on the ground.  The eggs hatch out nymphs, which are wingless and drop to the ground.  Nymphs dig into the ground, begin a journey of 13 years in the soil quietly and unseen. Nymphs have a sucking-mouth and feed on sap of roots of trees and plants. Fried nymphs make a great tasty, high protein value dish on the table.  After the 13-year growth, winged adult cicadas emerge out, climb onto trees, and sing extremely loud and incessant from morning to dusk, declaring their appearing after 13-years hiding under ground and calling for mates. Only males sing, females are mute and voiceless.  Cicadas are basically harmless, except the egg-laying damages to twigs and stems of trees and shrubs. Whether you like the cicada “song” or dislike the “noise” is up to your judgment.  The next occurrence will be in 2024.

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