Annual Cicadas Have Arrived (2018)
By Julia A. Keirns
In Ohio there are two types of cicadas that may appear: the annual cicadas, sometimes called “dog-day” cicadas; and periodical cicadas that only appear every 13 or 17 years. 2018 was not a year for a major emergence of periodical cicadas in Ohio, according to Curtis Young, Extension Educator at the Van Wert County, Ohio Extension Office.
In recent days the annual cicadas (Neotibicen spp.) have surfaced. The warm humid nights have allowed the temperature of the ground to warm up enough for them to emerge from the soil. It is a yearly event, signifying hot summer nights. These annual cicadas are fairly large, have mostly black/brown bodies with green markings and clear wings.
Many people mistakenly refer to these insects as locusts. It is believed that many years ago, early European colonists mistakenly labelled the cicadas as locusts, and the name stuck. Locusts are actually a type of grasshopper though and are not what we hear every evening singing their songs.
It is a common understanding that with the appearance of the cicada, there is only six weeks left of summer warmth. The life span of the cicada once above the ground is only 5 or 6 weeks, so it is thought that the warm summer nights will fade as well. “I hope that isn’t true though,” stated Young. “I heard my first dog-day cicada singing on June 29. Hopefully, summer does not end in the middle of August!”
Periodical cicadas emerge in large groups, sometimes numbering in the millions and their evening song can be deafening, depending on the number of cicadas in any particular tree. The mating call can be in excess of 120 decibels. In comparison, a chain saw or oxygen torch both have a decibel level of 120. Multiply that times hundreds of cicadas, and it is definitely loud.
“Fortunately,” stated Young, “dog-day cicadas emerge in much smaller numbers with only a few in any given tree and a few hundred to a few thousand in a village or town…much more tolerable!”
Cicadas go through a variable number of instars (growth stages) in their life cycle, several of which occur underground. As with almost all insects, cicadas start life as an egg which was laid in the branch of a tree by the adult female. When the egg hatches, the nymph (immature) drops to the ground, burrows into the soil, finds a tree root, and begins its feeding by sucking juices out of the root. These nymphs will spend 3-5 years underground and develop through 3-5 nymphal instars. When they are fully matured, each nymph will emerge out of the soil, climb the nearest tree or any other object near to them, and shed its final exoskeleton on the bark. At that point they are adults and their main purpose in life is to find a mate and lay eggs for the next generation.
“The songs filling the air till dusk are those of the males producing their mating call. Each species has its own unique song like different species of songbirds. Listen closely and see if you can detect the differences,” said Young.
Every insect has a purpose and cicadas are no different. They are beneficial in three ways. They aerate the soil when they emerge. They prune weak branches from the trees. After they die, their decaying bodies release nutrients into the soil. They also are beneficial to the food chain, as any animal will eat cicadas including dogs and cats.
“The cicadas are not toxic,” he noted, “but some dogs and cats will vomit after eating them, mostly from over indulging.”
Cicadas do not bite or sting, but they may mistake humans for a tree and try to pierce and suck the skin. Cicadas mean no harm. Simply place them back on the tree and they will go on about their business.
Warm summer nights are here. Enjoy the songs of the cicadas before they go away for another year.
For more information on cicadas, visit the Cicada Mania web page at: www.cicadamania.com, or read articles and fact sheets by OSU Extension at: Annual Dog-Day Cicada Emergence, https://bygl.osu.edu/node/420 and Periodical and “Dog-Day” Cicadas, https://ohioline.osu.edu/factsheet/ENT-58.