You may have heard that this is the year for 17-year periodical cicadas to emerge in Greater Cleveland. They’ll be emerging in much of Eastern and Central Ohio and West Virginia as well. So what are these critters? And how are they any different from the cicadas we see and hear every year? What do we know about them and what do we need to know about them before they show up in our neighborhoods, on our trees and maybe following us around as we mow the lawn?
Cicadas are insects in the order of true bugs or Hemiptera. A true bug is identified by its mouth parts which are adapted for sucking. Cicadas along with most true bugs feed by sucking plant juices from a mouth that looks like a long straight straw. Their closest relatives are aphids, stink bugs and water boatmen.
While we can see many different species of cicadas locally, they can be grouped into two categories: annual cicadas and periodical cicadas. Annual cicadas are the ones we see and hear every year. They are greenish and black in color and emerge from the ground in mid-summer. Their calls that we hear most often are the soundtrack to the summer breezes as they call, “ch-ch-ch-ch-ch” rapidly up in the trees.
Periodical cicadas emerge only every 17 years in Northeast Ohio (some species emerge every 13 years in more Southern states). We see them earlier in the year than the annual cicadas; they emerge in May when the soil reaches 64⁰F. These 17-year cicadas are black with red eyes and orange wing veins. The colors are vivid and add to the mystique of their strange life-cycle. The calls of the 17-year cicadas are buzzier than their annual relatives, “Whahhhhhhhhhhhh”. We’ll see these cicadas only for about 3-5 weeks after their emergence.
The periodical cicadas we will see this May and June have been living underground as juveniles, known as nymphs, since they started life as an egg in 1999. They have fed on tree sap that they sucked from the roots deep underground. They haven’t seen the light of the sun, or an above ground predator in seventeen years.
periodical cicada nymph
When they emerge in May we’ll see them first in this nymph stage. They are golden in color and have red eyes. They are slow and clumsy crawlers, reminding me of little dump truck-like bugs. They’ll move toward a surface like a tree trunk or the side of your garage to change into an adult. You may see a few in an area, or there may be up to several hundred per square yard in the heaviest populated areas.
When the cicadas are ready to emerge as adults, their juvenile shell will split up the back and the adult will squeeze its way out of this split. The adult will be cream colored with red eyes. It takes the adults a day or two to expand and dry their wings and change to the characteristic black color. They are at their most vulnerable during this time. A few days more and the males will begin to make their calls, a loud buzzing whine that can sound almost constant in an area with a heavy emergence.
newly emerged adult cicada, it will darken and expand its wings in a day or two
The males call to attract female cicadas. The females fly to find them and make some clicking noises with their wings to signal their reception to the male. The cicadas will mate with their posterior ends together, facing in opposite directions. Females will carve troughs in tree twigs to lay up to 300 eggs. The new cicadas will hatch from the eggs as tiny nymphs, fall to the earth and enter the soil for 17 years of living and growing underground.
3 adult periodical cicadas
Some things to remember as you witness this spectacular natural phenomenon:
- Cicadas are not toxic. Predators and pets will eat them.
- Cicadas do not sting or bite. They will not try to poke you with their proboscis.
- Periodical cicadas will only be here in Northeast Ohio during May and June this year.
- You may live in area with few or no cicadas. Or you may be near a heavy emergence area where the noise and nuisance are significant. Just remember, it’s temporary.
- We strongly recommend that you do not try to kill or poison them with chemicals. There will be too many for you to eradicate them from your yard and the poisons will have the most negative impact on other nearby wildlife.
- Cicadas will not harm mature trees, even if you see some dying leaves. Cicada egg-laying may have an impact on very young or newly planted trees. If you have new trees that you’d like to protect from the cicadas, you can remove them by hand, by spraying the tree down with a hose each day, or by temporarily loosely wrapping branches with cheese cloth.
- Periodical cicadas are only found in North America. This is one of the world’s coolest natural phenomenons. Take a moment to enjoy the spectacle. Attend a Cleveland Metroparks program about cicadas or talk to a naturalist about a great place to go and see the emergence.
Keep checking back with Notes from the Field. Next month, as we look forward to the emergence, I’ll write some more about the timing of the 17 year-cicadas. Why do we only see them every 17 years and why do people in other places see them in different years? We’ll also have a Notes from the Field installment all about how you can be involved with some important 17-year cicada research.