Annual cicadas are making a racket
Stuck at home after surgery, and I'm noticing an amazing chorus of insects in the woods behind the WeatherDeck. They're the annual, or "Dog-Day" cicadas, (right) and they seem to be enjoying an unusually loud and busy summer in Maryland's trees.
University of Maryland entomologist Mike Raupp agrees. "I can't remember a year that the annual ... cicadas have been as abundant and active," he said in an email on Monday.
And how. Just off the WeatherDeck in Cockeysville you can see them flitting from tree to tree in search of that special someone, following the chattering, rasping chorus of come-hither songs. The noise seems to come in waves, rising and falling in volume as if they're all listening to each other and responding with ever-more vigorous refrains.
The insects almost drown out the air conditioners. Here's an audio clip from the WeatherDeck.
These are annual cicadas, among them Tibicen linnei, a separate set of species from the well-remembered 17-year periodical cicadas, or Magicicada, (left) that last emerged from the earth in central Maryland in May and June 2004. Known as Brood X (ten), they're due back in 2021.
Raupp had some speculation about what might explain the bugs' abundance this summer:
"Like with all bug-related issues this year, we are attributing the fine cool and wet spring to enhanced survival of many insects and superior quality of plants that serve as food. With many of the subterranean dwellers including termites and cicadas, getting out of the ground is critical. This is only speculation on my part, but I am guessing that moist loose soil coupled with nice humid conditions favor emergence and survival of these guys. Also, the glorious lush growth of trees and shrubs this year may be providing adults with abundant high quality food during their tenure above ground."
The annual cicadas we're hearing now are sometimes called Dog Day cicadas because they emerge and start their singing in mid-to-late summer, the "dog days" of summer.
It's an interesting expression. It evokes images of overheated dogs lazing about in dusty southern streets under oppressive heat and humidity.
If fact, the "dog days" label refers to the position of the sun at this time of year, near the bright star Sirius. Sirius, the brightest true star in the heavens (actually, a double star system), is also known as the "Dog Star" because of its position in the constellation Canis Major, the Big Dog.
Because Sirius is so near the sun in the daytime sky at this time of year, we can't see it. But it is prominent in the night sky in winter and spring, just to the left of, and below, the familiar constellation Orion.