SAN MARCOS, TEXAS — A strange and eerie song has been emanating from the trees of Central Texas in recent weeks, compliments of a giant cicada that rarely makes it this far north.
Since mid-June, the piercing call has been reported from San Antonio to Austin and in many of the nearby Hill Country communities.
"When I heard it, I had no idea what it was — I just knew it wasn't something that usually occurs," said Texas State University-San Marcos biology professor David Huffman. "At first I thought it was someone working with a router. And then I heard a second one. Then I realized it was coming from the tops of trees."
The sound stumped Huffman, who has lived in the area for almost three decades. . Eventually, with the help of a cicada expert in Connecticut who matched an audio spectrograph of the bugs' unique call, he was able to identify the species.
And although he's heard the call many times since then, Huffman has been unable to actually find one of the noisy insects. He's offered a $15 bounty for one — preferably alive — but so far, all people have come up with is the more-common dog day cicada.
The giant cicada is a prehistoric-looking bug that measures well over 2 inches from nose to wingtip. Adults are known to inhabit treetops, but immature bugs can spend as long as four years below ground eating tree roots.
The earsplitting insect is among the loudest on Earth, with a sound that has been often compared to a locomotive whistle. Unlike a cricket, which makes sound by rubbing its legs together, the cicada makes noise by "vibrating special membrane-like structures (tymbals) on their abdomen," according to a description from the Texas Parks and Wildlife Department.
The critter is common from far South Texas to Argentina. There are records of the insects in the San Antonio area in the 1930s, but not in recent decades. A few were documented last year, but they are much more prevalent this year, said Parks and Wildlife biologist Mike Quinn.
He doesn't have a definitive explanation for the re-emergence, but said climate change could have something to do with it.
"We're going through a warming period here on Earth, and lots of species are creeping northward," he said. "I know of no other reason than that."
For more information on the giant cicada, see www.texasento.net/Cicada.htm