This one is for parents, teachers, friends of children and nerds of all ages. This one is for anyone who has ever wanted to drop mad knowledge about the end of summer insect shrieking. The interwebs have allowed me to gather just a notch above the basic information along with some nerd style imagery to share with you about CICADAS, the not locust.
First things first. Take a look at the two images above. The first is an exoskeleton from a final molt or, to use a fancy word, ecdysis, that an adult has left behind. I’m sure you remember finding these as a kid and wearing them as jewels on your sweaters. No? Maybe it was just me. Anywho, the second image above is of an adult. Now, many of us as children were told by well-meaning grown-ups that these are locusts. They are not. These are cicadas.
Locusts and cicadas are different insects. They are as dissimilar as ladybugs are to butterflies. Locusts are a kind of grasshopper in the order Orthoptera. Locusts are a grassland insect. Cicadas are true bugs more closely related to stink bugs or boxelder bugs and are classified in the order Hemiptera. Cicadas live in and around trees.
Now that we have that straight let’s do a proper nerd out. Nebraska is home to 24 species of cicadas. There are two main groups. Most famous are the periodical cicadas, Magicicadas spp. Periodical cicadas have 13 to 17 year life cycles. These are the kind that get all the celebrity and huge write ups in the newspaper or outdoor magazines when they emerge The second group is named the dog day or annual cicadas. These are the kind I most often find and I’m sure you are most familiar with as well. Annual cicadas have two to five year long life cycles but the life cycles overlap so there is a batch emerging every summer.
Male cicadas are the screamers. Their call is what most calls are purposed for, attracting a mate. From approximately mid-July through the end of August males will just sit high up in trees waiting and screaming. When a female fancies a particular male she will fly up and land nearby making a clicking sound with their wings in response. After they do their carnal business the female will be laying, or be fancy and use the term ovipositing, her eggs within three to five days in late summer.
A female cicadas have an absolutely wicked way of ovipositing her fertilized eggs. She will use their ovipositor to saw slits in small living twigs or branches where she will deposit her 20 or so eggs in nests. When the eggs hatch they fall to the ground as nymphs and burrow 15 to 18 inches below the surface where they will continue to live, they do not hibernate, burrowing and sucking the xylem from plant roots.
The nymphs will grow through several instars, or growth stages. Cicadas go through incomplete metamorphosis so they have no pupal stage. In their emergence year fully grown nymphs will move above ground leaving behind ½ inch exit holes and will crawl up trees, house siding or picnic table legs to attach themselves for their final larval instar. During this instar their exoskeleton will harden and the adult will molt through a crack in the thorax. What is left behind are the shells we see clinging to tree trunks and other surfaces. The adults that emerged will live two to four weeks.
I wrote earlier the males are the screamers. Their little screamer gadgets are so COOL! They make their classic end of summer mating call using tiny instrument called a tymbral organ. It’s a thin membrane, only a ¼ inch in diameter, attached to muscles that they will shake like ‘flapping a sheet in the wind’, but super-fast. Their abdomen is partially hollow and curved serving to amplify and project the sound, similar to a tuba or trumpet.
To close down this show I would like to add, know your audience when you are bequeathing unto them your new found cicada nerdom. I only know of a handful of first graders, and less grown-ups, that care what order cicadas are in. I find, especially in adults, all we need do is guide the inborn sense of wonder and curiosity. Then when a question is asked you can delve as deep as needed or request. Don’t get distracted by the science but use it to immerse yourself and others in the awe of the world around us.
As always, I did do the nerd search but I could have gotten my wires crossed somewhere. I also pulled a bunch of this out of my brain. I am not an expert so please let me know if you think I may have misunderstood any of my research.