Cacophony of Cicadas
By Dan Zarlenga, Missouri Department of Conservation
You might already be hearing them. Unearthly whines, buzzes and rasps coming from the trees and shrubs around you. Maybe they sound like alien communications, or perhaps a synthesizer gone mad. No need to fear, they are just our yearly visitors, the annual cicadas. These insects may make a lot of noise, but their buzzes are worse than their bites.
Annual cicadas are a group of insects made up of several different species that emerge each year as the temperatures climb in mid-summer. They reach their peak of activity in July and August. People may call this time the “Dog Days of Summer”, but it seems like cicadas are the ones calling all the shots!
Adult annual cicadas tend to have black, green, or olive-colored bodies, often with a whitish cast on the underside. Their eyes are either black or brown, and they have four membranous wings with a black or green tinge. They crawl and fly but unlike crickets and grasshoppers, they can’t jump. For most of their existence, annual cicadas live underground and use their sharp, straw-like mouthparts to feed on juices from tree and plant roots. Their winged adulthood above ground lasts only a few weeks in summer when they emerge to reproduce. That’s when we hear them, as they call for mates from wooded areas, parks, and forest borders.
You can almost set your watch on a summer’s day by knowing which species of cicadas are calling, as each one takes on a specific shift. The swamp (also called morning) cicada starts off the day with a buzz lasting 8–12 seconds that intensifies to a rapid pulsing “chatter” before dying away again. Later in the morning and into midday, you might here the Robinson’s cicada. It’s rhythmic, repetitive, “zee-ape, zee-ape” call peaks around noon.
By the heat of the afternoon the buzz saw cicada chimes in with a single-pitched, electric-sounding, sizzling buzz lasting 30–60 seconds. As the day gets later, the northern dusk singing (or big) cicada gets in on the act and produces a winding up buzz that gets gradually louder and ramps up to an accelerating “Dirrrrrr, Dirrrrrr, Dirrrrr, Dirrrr-Dirrr-Dirrr-Dirr-Dirr-Dirr”. It’s often joined by the Walker’s cicada, one of our loudest cicadas. It belts out a pulsing, repetitive rasp that sounds a little like “jeeb-jeeb-jeeb-jeeb-jeeb-jeeb-jeeb”.
Finally, we’re treated to the scissors grinder cicada, and its distinctive “WHEE-oo, WHEE-oo” or “WHEE-yer, WHEE-yer”. It really does sound like a grindstone sharpening scissors, continuing from dusk and into the early evening.
By nightfall, the cicadas retire and grow quiet. The after-dark hours of summer are ruled by the calls of the katydids and crickets.
They may sound weird, bizarre, or unusual. But like that oddball relative who visits every holiday and talks a lot, annual cicadas have a quirky charm that we’d miss if they weren’t there. And our summers wouldn’t be the same without them.