Cooley and his colleagues have even discovered that the insects can jam crucial sections of their rivals' love calls. "This is not a friendly little cooperative chorus," he says. "These are males fighting tooth and claw to drown out the other males."
Maryland is home to 15 kinds of cicada - four periodical and 11 annual species. Periodicals attract the most attention - and create the most chaos when they emerge from the soil every 13 or 17 years.
Leaving their roots
Often mistakenly called "locusts" (which is technically a type of grasshopper), periodical species spend all but a few weeks of their lives underground, sucking nutrients from tree roots.
When the time comes to emerge - scientists still don't know how the creatures keep track - they dig neat, round escape shafts to the surface. Their arrival is usually dramatic, since they typically all show up within a few days.
Finding a vertical perch, the young cicada nymphs split their dry skins, and pale, winged adults climb out to begin an urgent search for mates. That's when the singing starts.
After they mate, the female cicadas lay up to 600 eggs into cuts in the tips of tree branches. In six to eight weeks, the eggs hatch. The nymphs drop to the ground and burrow into the soil to feed for another 13 or 17 years, leaving their parents to die.
While cicadas are harmless, periodic cicadas emerge in such numbers that they can create havoc. Their intense noise can cause outdoor cafes to close, while their intense numbers can drive school graduation ceremonies and weddings indoors.
Some Marylanders are already bracing for the imminent arrival of a group of 17-year cicadas known as brood X. The largest of the periodical cicada groupings, it last invaded Maryland in May 1987.
Gaye Williams at the Department of Agriculture says she has begun taking calls from frantic brides preparing for spring weddings. Her advice: Forget shrimp dip. And if you do serve it, she says, "Don't eat the lumps."
Information: Cicada Mania, www.dancentury.com/cicada