By Celeste Silling
The other day, a coworker of mine asked me about cicadas. “Weren’t there a ton of cicadas here last year at this time?” he wondered. And he was right. Here at Gulf Coast Bird Observatory headquarters, you couldn’t walk down a trial last spring without being overwhelmed by the dull, echoing screeching of cicadas. But now, I can barely hear them at all. Why could that be?
Fear not bug lovers! The cicadas are not going extinct. Rather, they are buried underground.
Cicadas, broadly speaking, are a huge group of insects, with over 3,000 species around the world. Some of the most interesting species are called Periodical Cicadas of the genus Magicicada. These, like other cicadas, have large eyes set wide apart on their head, short antennae, and long wings. The males also have an extremely loud song that they create using part of their exoskeleton.
Unlike other cicadas, Periodical Cicadas emerge periodically every 13 or 17 years in a synchronized uprising. This means that during certain years, the southern U.S. states are absolutely thrumming with cicadas during spring and summer until the adults die off. They live in trees, feeding on sap and laying their eggs in the bark. The eggs mature for about six weeks, then the larvae fall to the ground and burrow down in the dirt. There, they lay in wait for 13 or 17 years, until its time to surge upward.
What could be the benefit of this lifestyle? Well, the unusual timing of this emergence could reduce predation. Cicadas are loud, awkward, and fairly chunky, making them easy pickings for predators. But by staying underground for over a decade, Periodical Cicadas keep their emergence more or less a “surprise” for the predators, who can’t rely on them as regular prey. And by emerging all at once, they can more easily find each other to mate.
Here in Texas, we don’t really get too many Periodical Cicada emergences. The last documented one that I could find was in 2015 and it won’t happen again until 2032. But that doesn’t mean we don’t see our fair share of cicada swarms! There are over 40 cicada species that naturally occur in Texas, which are called Annual Cicadas. They’re just as fun as Periodical Cicadas (if you enjoy screeching insect noises coming from all directions).
Annual cicadas come out every 1-9 years depending on the species, and their emergences are not as coordinated. While the Periodical Cicadas come out all at once, Annual Cicadas are more staggered. This means that every year there will be some cicadas emerging, and some years will have many more than others.
This spring, from all appearances, does not seem to be a banner season for cicadas. Hopefully this summer will have more, as different species crawl up from the ground. But if not, we bug lovers can still rest easy… there’s a whole world of cicadas beneath our feet, just waiting to emerge!
Photo by Dan Century
Caption: Magicicada (Periodical Cicada) on a leaf.
