The return of the cicadas
Published 8:39 pm Tuesday, July 14, 2015
By Biff and Susan Andrews
I hate to do bugs two weeks in a row, but naturalists get interested in what they see around them. Last week it was ticks because of a tick bite. And two days ago we saw a cicada emerge from its nymph shell, dry its wings, and fly away. So some research was in order — 17-year locust or more common?
The beginning of wisdom is to understand how much one doesn’t know. Boy, did I not know about cicadas. There’s lots to know.
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The basics: There are 3,390 species worldwide. The long-term broods — 13- and 17-year cycles — are numbered in capital Roman numerals, and their emergence years are well known in any area. In 2015 we are experiencing Brood IV (a 17-year species) and Brood XXIII (a 13-year species). But the one we saw shedding its nymph skin was neither, because it’s too late in the year.
The 13- and 17-year groups are out of the ground before the end of June.
(If you really want to know how much you don’t know, try learning why these cycles are prime numbers!)
Obviously we’re dealing with an annual species — of which there are 25 in Virginia, you’ll be happy to know. Most have reddish-orange eyes and black backs, with diaphanous wings.
So here’s their life cycle:
- They hatch from an egg and become a wormy nymph.
- They drop to the ground and burrow down to some succulent roots.
- They create a cell, a groove in the roots hardened by their own excretions.
- Long-term species may molt three times.
- They build a tunnel (even a tower? a chimney?) to above ground and emerge.
- They “run” to a vertical surface to molt.
- They shed their nymph skin, change color, harden their bodies and wings and fly.
- Males make a loud noise (don’t they always?), thereby attracting females.
- They court and mate (same old, same old).
- Females lay the fertilized eggs in branches of plants and trees.
- They die.
So much for the meaning of life.
Now, to debunk some myths.
4These are not the locusts of Biblical story, though those were cicadas.
4They do not seriously damage trees and shrubs — perhaps a few casualties here and there, but why kill the thing that gives you life?
4Most cicadas are not of the 17-year-locust variety.
If you want to see where they may be emerging, look for exit holes, towers or chimneys at the bases of trees. Kids love empty nymph shells clinging to trees. Late in the summer, you’ll find their corpses on the ground or attached to trees. But chances are, you’ll hear them before you’ll see them. They’re in full voice right now.
Susan and Bradford “Biff” Andrews are retired teachers and master naturalists who have been outdoor people all their lives, exploring and enjoying the woods, swamps, rivers and beaches throughout the region for many years. Email them at email@example.com.