I stride across the prairie, stepping around prickly pear and cholla cacti. I’m looking for fox and badger dens, but a huge flying insect distracts my attention. A cicada drones as it loops overhead and bumps into my cheek. I remember we called them chicharras when I was growing up in Texas. The word means both buzzer and cicada in Spanish.
It is still spring, yet the sun’s heat bears down on my back and shoulders. Sweat trickles down between my shoulder blades. I remove my cowboy hat to wipe my brow. Chicharras like the heat. I accidentally step on a dead one, its brittle exoskeleton crunches beneath my boot.
The world vibrates. An electric buzz shoots through my head … zzzzzZZZ, rising to a shrill alien shriek. Alarmed, I jumped. For a millisecond my mind thinks rattlesnake; although I immediately realize it’s not the right sound.
The common cactus dodger (Cacama valvata) is a large gray-black species of cicada associated with cholla cacti, common in southeast Colorado. When disturbed the cactus dodger makes this shrill, ear-splitting alarm, the loudest produced by any species of Colorado cicadas.
The eastern North American “periodical cicada” genus Magicicada emerges synchronously by the billions after either 13 or 17 years underground, depending on the region, as some did earlier this year. On the other hand, the cactus dodger nymph emerges onto the prairie each year after living just a few years as nymphs where they remain burrowed underground sucking sap from roots. In spring they tunnel upward crawling to the surface, climb up cactus stalks, and creep into the branches. As metamorphosis completes, their nymphal husk splits down the back. The adult form then crawls forth and unfurls wrinkled wings by pumping hemolymph throughout the wing veins.
I recall a cicada hatch on the Green River in Utah. The adult insects droned as they flew over the river dropping into the water. They vibrated in the surface film drawing an audience from deep-green pools. A feeding frenzy ensues as large trout rise to take beefsteak-sized insects.
No river here. Yet the numerous cicadas provide nourishment to a variety of creatures. All manner of birds swoop down to pick the giant bugs from branches or out of the air — lark bunting, ravens, magpies, grackles, jays, thrashers, and kestrels. Mississippi Kites that live along the gulf coast, but have recently extended their summer range into the Arkansas River Valley of Colorado, subsist largely on cicadas while here. Along with a variety of grasshoppers and caterpillars there is an abundance of bugs to feed nestlings.
So too swift foxes will feed on them. During summer, adult foxes live largely on insects while saving the prairie dogs or pocket gophers they have caught for their kits. Under night’s darkness grasshopper mice and shrews scurry out to collect up those cicadas that have dropped to the ground or hang clinging to low grasses.
The air is thick with a pulsating drone, the synchronized song of the male cicadas. While clinging to the branch of a cholla cactus, a male rapidly percusses a corrugated membrane on its abdomen called a tymbal producing high-frequency clicking vibrations that resonate in chambers within its body. Its droning song is alluring. A female likes the male’s drumming and comes ever closer ticking her wings, she releases enticing pheromones. Soon they mate.
The sound of a cactus dodger. Video by Rick Destree.
The adults live about four to six weeks after emergence. Once they’ve mated, the female lays her eggs in a small slit she makes on the cactus surface; this does very little damage to the plant. Soon after she dies. After a few weeks the nymphs hatch, drop to the dirt, and burrow under the surface. They will dig in deep before autumn brings the first chill to the prairie.
As land is plowed under for agriculture or converted to an urban landscape, cicada populations continue to diminish. Like other cicadas, the cactus dodgers can be an early indicator of declining health of the cholla prairie. But this year, as usual, the Chico has a bumper crop of flying chicharras.
Other Cicada Facts
- Cicada are of the order Hemiptera or the ‘true bugs’.
- Some Cicada produce one of the loudest noises known at 120 decibels, which can cause hearing loss in humans.
- Lawnmowers and power tools will often attract cicadas.
- Some scientists believe that lifecycles of the periodical cicada are 13 or 17 years, which are prime numbers, so their emergence is less predictable to predators.