Periodical cicadas have been found here in the United States for hundreds of years. It is recorded that in 1633 the governor of Plymouth colony wrote of the periodical cicadas and that no English man had ever seen them before or since. It would be another 200 years before we had a grasp on periodical cicadas populations. Dr. S.P. Hildreth from Marietta, Ohio helped confirm that cicadas have a 17 year life cycle, but confusing the matter even more was that cicadas in southern states have a 13 year life cycle. The cicada populations were put in to an ordered system in 1898 by Charles L. Marlatt. He numbered the emerging cicadas with roman numerals, because there were 17 possible emergence years; numbers 1 through 17 were reserved for the 17 year cicadas and numbers 18 through 30 were to be used for the 13 year cicadas. Even though there could be 30 possible groups “broods”, there are in fact only twelve established 17 year broods and three 13 year broods. Here in Ohio we have four established broods V,VIII,X,and XIV. Brood V will be the next to crawl from the ground in 2016.
When it is time for them to appear, the nymphs emerge from the soil at night and climb onto nearby vegetation or vertical surface, where they then molt into winged adults. The emergence is often tightly synchronized within a few nights. Adult cicadas live for only two to four weeks. During this time they don’t feed much, instead the males gather in groups and sing, by vibrating membranes on their abdomen. The females quietly choose a mate and then lay their 400 eggs in twigs of trees; the egg remains in the twigs for six to ten weeks before hatching. During this time flagging can occur. Flagging is when the twigs break where the eggs were laid and the leave on the twigs die. The newly hatched nymph falls to the ground where it burrows 6 to 18 inches underground to feed for 17 years.
The cicada’s survival is linked to the mass appearance. As part of their survival strategy, they appear in such great numbers that predators cannot eat all of them and ones not consumed reproduce and continue the cycle. Periodical cicadas are a unique part of our ecosystem and provide a break from the monotony when the broods appear.
More information on periodical cicadas can be found at Ohio Biological Survey, and through OSU Extension.
Submitted by Joe Lehman, Wildlife/Forestry Specialist
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