Adult annual cicadas have black, green, or olive-patterned bodies, often with a whitish cast on the underside, black or brown eyes, and 4 membranous wings with a black or green tinge. They crawl and fly but do not jump. The mouthparts, tucked beneath the head, are like a small, sharp straw. The antennae are short, and there are 3 ocelli (eyespots) in addition to the 2 larger, compound eyes. Compared to periodical (13- or 17-year) cicadas, annual cicadas are larger. Adult males have a sound-producing organ that emits a loud, raspy call used to attract females. Different species, such as the scissor grinder and buzz saw cicadas, have distinctively different types of calls and call at different times of day. Adult females have a curved ovipositor at the lower end of the abdomen, used to insert eggs into slits in twigs.
Nymphs are tan or brown, wingless, stout, with the front pair of legs specialized for burrowing in soil and for clinging onto trees as they undergo their final molt into adults.
A number of annual cicada species occur in Missouri. They can often be identified by their song, and the time of day they sing. Some notable species include
- Robinson's cicada (N. robinsonianus): has dark wings, a complete black "face mask," a white stripe across the back, and a black stripe on underside of abdomen; associated with upland forests, limestone outcrops, especially places with plenty of eastern red cedar and other juniper species, including nurseries. Call is a repetitive, rhythmic "pZEE-ape, pZEE-ape." Mostly calls in midday, from midmorning to early afternoon.
- Scissors grinder cicada (N. pruinosus): a green cicada with a white stripe on its sides; there is no stripe on the underside; our most common annual cicada; wooded areas, including suburban locations and along streams. Calls from high in trees; distinctive "WHEE-oo, WHEE-oo" or "WHEE-yer, WHEE-yer" (sounding a bit like an old-fashioned treadle-powered grindstone being used to sharpen scissors, knives, or other tools). Mostly calls in the evening and at dusk in the dog days of July and August.
- Lyric (or buzz saw) cicada (N. lyricen): a reddish yellow and black cicada with a thick "collar" behind the head that is mostly or all black; has patterned green or brown pronotal (shoulder) patches; legs dark brown or reddish brown; dark stripe on underside of abdomen; lives in deep hardwood forests, high in trees, often along streams. When handled, this cicada often tucks up its legs and "plays dead." Calls from high in trees; song is a single-pitched, almost electrical-sounding, sizzling buzz lasting 30–60 seconds.
- Northern dusk singing (or big) cicada (N. auletes; sometimes Megatibicen auletes): has a brown collar and is solid tan underneath; often covered with a gray powdery "bloom"; nearly 2 inches long, the largest cicada in North America; adults are seen from the end of July to mid-August; associated with oak woodlands. Calls begin with a long "winding up" buzz that gets gradually louder and ramps up to a rhythmic, gradually accelerating "Dirrrrrr, Dirrrrrr, Dirrrrr, Dirrrr-Dirrr-Dirrr-Dirr-Dirr-Dirr . . ." and ends with a long, diminishing, croaking buzz ("rrrrrrrrr . . .") that is the reverse of the "winding up" buzz, before tapering off completely.
- Swamp (or morning) cicada (N. tibicen, formerly T. chloromera): a black cicada with green shoulder patches; and a white spot on each side where the abdomen meets the pronotum (the plate behind the head); abdomen is white; lives in shrubs or tall weeds in low, swampy areas or along river banks. Call lasts about 8–12 seconds: a buzz that intensifies to a rapid pulsing "chatter" before dying away again. It's called the morning cicada because it calls from about 8 to 11 in the morning.
- Walker's cicada (N. pronotalis; sometimes Megatibicen pronotalis), is one of our largest cicadas and has bold black patterning with bright or olive green and rust, orange, or tan. Eyes often bluish or grayish. It is one of our loudest cicadas, calling with a pulsing, droning rasp ("jeeb-jeeb-jeeb-jeeb-jeeb-jeeb-jeeb . . .") in late afternoon and evening during the hottest part of summer. The alarm squawk is especially loud.
- Prairie (bush, grand western, or splendid prairie) cicada (N. dorsatus; sometimes Megatibicen dorsatus): ornately patterned with lines and spots of rust, tan, black, and white. Eyes often tan or brownish. Breaking the usual cicada trend of living among trees, this species is associated with tallgrass prairies as well as nearby woodlands. Because tallgrass prairie has been nearly eliminated from our continent, this once-common insect is now limited to prairie remnants. It calls from grassland vegetation; its long, steady, rattling, dry, buzzy song lasts about a minute before tapering away into an electric buzz.
Length: to 2 inches.
Habitat and Conservation
Annual cicadas are most common in forested and wooded areas, parks, and forest borders, as eggs are laid in tree twigs and nymphs depend on tree roots for their nourishment. As winged adults, cicadas can fly anywhere, such as into nearby pastures and fields, but they rarely go far from the trees, from which males do most of their raspy calling and where the females lay their eggs.
Annual cicadas are common throughout the state. In addition to preferring areas where trees are abundant, cicadas also succeed in areas where the land is left relatively undisturbed for the few years it takes the nymphs to grow. Because the nymphs live underground, suck juices from plant roots, and then must crawl out of the ground, large earthworks, deforestation, insecticides, enormous paved parking lots, and residential and commercial developments can decrease populations locally.
Cicadas, like most true bugs, have sucking mouthparts like small, sharp straws. Cicada nymphs live underground, sucking from the roots of trees and other plants. Winged adults can suck plant juices, too, although they live for only a few weeks aboveground. It is very uncommon, but if you let a cicada sit quietly on your hand or arm for a long time, it may jab you with its mouth, mistaking you for a plant — painful, but a harmless accident, and certainly not an act of aggression or even defense.
Until quite recently, most annual cicadas were placed in genus Tibicen, but researchers determined that the group actually comprised subgroups worthy of being called separate genera. Thus only some European species remain in genus Tibicen, while a majority of North American annual cicadas are in the newly created genus Neotibicen. Some authorities further separate some species into genus Megatibicen. Some species in the US west have been placed in the new genus Hadoa.
Cicadas begin life as an egg laid in a slit of a tree twig. Some species lay eggs in living twigs, others in dead twigs. Upon hatching, the tiny nymph drops to the earth and burrows down, where it will live most of its life, sucking juices from plant roots. The nymphs of annual cicadas remain underground for 2–5 years. When ready, during the dog days of July and August, they claw to the surface, climb a tree or other object, and molt to become a winged adult. The shed skin remains behind, while the adults sing, mate, and produce the next generation. These animals are called "annual cicadas" because each year, some members of the species emerge as adults.
Annual cicadas are a big part of the beauty of Missouri summer evenings. The days may be oppressively hot and humid, but at sunset we can sit on our patios and porches and enjoy the sounds of cicadas, nighthawks, and chimney swifts, and the final, fussy calls of daytime birds as they prepare to put their bills under their wings. As it darkens, lightning bugs and stars start to twinkle, the cicadas quiet down, and the rasping katydids and chirping crickets begin the night shift as bats flitter silently above, hunting beetles and moths.
Though it may seem strange to us, people in many countries eat large, meaty cicadas regularly.
Cicadas are a popular bait for anglers.
Because of the predictable timing of their emergence in the dog days of summer, the first soundings of annual cicadas figure into folk wisdom, such as calculating the number of weeks to the first frost. In Missouri, we typically start hearing annual cicadas in early July, and the date of first frost is in mid- to late October (both events depend on your location within the state and can vary somewhat each year). In our state, it's probably close to 16 weeks between hearing the first annual cicada calls and receiving the first frost.
Annual cicadas are called dog day cicadas because they are present as adults during the so-called dog days of summer. The name comes from the late-summer prominence of the star Sirius in the night sky. Also known as Alpha Canis Majoris (the alpha, or brightest star in the constellation Canis Major, the "greater dog"), Sirius is the brightest star as seen from Earth. The next-brightest star is only half as bright! A main reason it looks so bright is that it is only about 8.6 light-years from Earth. In the Northern Hemisphere, Sirius and Canis Major have been associated with late summer events, including the annual flooding of the Nile, and what the ancient Greeks first dubbed as the hot, sweltering "dog days." The name Sirius, itself, is from the Greek word for "glowing" or "scorching." Its twinkling in the unsteady late-summer atmosphere seemed to be a sign of its radiant, evil emanations. People thought it caused lethargy, fevers, droughts, and dog illnesses. It's hard to visualize bright Sirius and its nearby stars as anything resembling a dog, but the group is positioned just to the lower left of the constellation Orion (the hunter), and it faithfully follows him each evening across the sky. Nearly every ancient culture had a unique name and mythology for the brightest star in the sky. Perhaps we could start calling it the Annual Cicada Star.
Many species of birds, insects, spiders, and other animals feed on these large bugs. Cicada killers are a remarkably large species of wasp that specializes in capturing annual cicadas and feeding them to their young.
The deep incisions that female cicadas make in twigs of trees when they lay eggs can weaken and break those twigs, thus serving as a natural pruning process.
The burrowing of nymphs aerates the soil.