NEBRASKAland Magazine is dedicated to outstanding photography and informative writing with an engaging mix of articles and photos highlighting Nebraska’s outdoor activities, parklands, wildlife, history and people.
Issue link: http://mag.outdoornebraska.gov/i/695082
I n the summer of 2015, Nebraska and several other states in the Midwest bore witness to one of the biggest natural spectacles in the world, and it all revolved around insects. The emergence of periodical cicadas, also known by the name of their genus "Magicicada," only happens once every 17 years and lasts just a few weeks. This event is much harder to overlook than other insect occurrences, though, due to the extremely loud calls of the cicadas as they congregate. There are around 150 species of cicadas in the United States, but their bright red eyes and deafening calls make periodical cicadas unmistakable. Before long they overwhelm trees and call with a persistence that comes from the fact that they only have several weeks to complete their life cycle. This particular group of periodical cicadas known as Brood IV, or the Kansan brood, consists of three different species that all emerge in unison and cover approximately the same area of the country. Cicadas are not locusts and will not decimate crops as other mass emergences of insects can. They also do not sting or cause injury, so it is a great privilege to be able to watch, and listen to, this rare event that happens right in our backyard. The vast majority of the life of a periodical cicada is spent underground as a juvenile. These 17 years are not slept away in a dormant state, as the nymphs burrow around feeding off of the xylem fluid of plant roots and grow, however slowly. As they emerge, they are one step away from adulthood and are not yet fully developed, so they must climb onto nearby vegetation and molt their exoskeleton one last time. Casting off this shell (known as an exuvia), they are vulnerable and cannot yet fly, so they must stay on this low lying perch and hope they do not become prey for one of the many animals that takes advantage of this sporadic occurrence. Because they are such visible and vulnerable insects, periodical cicadas must rely on the odds that come from strength in numbers to avoid being eaten. Local predators take full advantage of these easy meals and consume them en masse to such an extent that there have been noted booms in predator populations in the years following an emergence. However many are eaten during this time period, the tactic of relying on others being eaten first works for some, and the lucky ones are able to complete their life cycle, replenishing the population for another generation. Craw ling higher up into the trees, the males will congregate and begin calling in an effort to attract their JULY 2016 • NEBRASKAland 31 PHOTO BY JEFF KURRUS