The Free Press, Mankato, MN


September 11, 2013

Unsightly but harmless, cicadas becoming more common

Many people are noticing cicadas now. Despite their appearance, they are harmless to people and property.

An adult cicada is a large, one-inch long, stout insect with a green or brown body with black markings. Cicadas have four fly-like wings; the first pair is much longer than their abdomen which they hold tent-like over their bodies. They also have very short antennae.

There are two basic types of cicadas, dog day (also called annual) and periodical cicadas. Dog day cicadas (Tibicen spp.) do not have a synchronized life cycle so there are some that emerge every year in Minnesota. Periodical cicadas which do not occur in Minnesota spend 13 or 17 years as a nymph in the ground and then emerge together in tremendously large numbers.

While cicadas are present here from July into September, they are more often heard than seen. They produce a high-pitched sound during the day that resembles a powerline hum. Only the males produce this sound in order to attract females. They produce this hum by vibrating a membrane in an internal air chamber.

More commonly, people see the immature nymphs. They are dark brown and similar in appearance to the adults except that they lack wings. Some people think they look like beetles (perhaps because of their stout shape and that they lack wings) The nymphs are subterranean during their lives spending four to eight year underground feeding on tree roots.

Once they emerge from the ground, they climb up objects such as trees, posts, fences, and even the sides of buildings to finish their development. When cicada nymphs molt into adults, they leave behind "cast skins." Sometimes it is not until these empty shells are closely examined that some people realize that these are no live insects.

Fortunately, cicadas are not harmful or dangerous to people, pets, or property in any stage. While they do feed on trees, they do not cause any noticeable injury. If you see cicadas, just ignore them and they will eventually go away on their own. No control is necessary.

Text Only | Photo Reprints
Hyperlocal Search
Premier Guide
Find a business

Walking Fingers
Maps, Menus, Store hours, Coupons, and more...
Premier Guide
NDN Video
Alicia Keys is Pregnant With Second Child Justin Bieber Takes To Instagram To Diss Orlando Bloom Did Jimmy Fallon Look Up Heidi Klum's Dress? 'Bachelorette' Star Nick Viall Talks Intimate Experience with Andi Dorfman Jessica Alba Sizzles on the Cover of Maxim Allison Williams Shares Peter Pan Throwback Pic Kim Kardashian Defends Brother Rob Against His Ex Adrienne Bailon Bradley Cooper And Sienna Miller Working Together Again You Won't Believe the Celeb Cameos in "Sharknado 2" Legs For Days! Megan Fox Rocks a Silver Mini Is Nick Viall Next for "The Bachelor"? Beyonce Fires Back at New Breakup Rumors No Man, No Problem! Katy Perry Talks Babies Jeah! See Ryan Lochte's 10,000 Calorie Diet "Guardians of Galaxy" Cast Shares Inside Scoop Allison Williams Will Star as Peter Pan in Live TV Broadcast Orlando Bloom 'Takes a Swing' at Justin Bieber In Ibiza Drew Barrymore's Half-Sister Found Dead Orlando Bloom and Justin Bieber Reportedly Came To Blows In Ibiza Ariana Grande's Troubled Relationship With Father