Many of us midwesterners have yet to hear one of the most familiar midsummer sounds. Isolated series of electronic buzzes begin in mid-July. Within a few weeks, the isolated buzzing builds to an ear-splitting, loosely coordinated chorus. The singers are male dog day cicadas (Tibicen canicularis).
Found throughout the northeastern U.S. and southeastern Canada, dog day cicadas can be encountered wherever there are mature trees. Nymphs feed underground on root plant juices. Adults, who have emerged from the ground, do not feed. Their aboveground actions are focused entirely on producing the next generation of cicadas.
Males make a sawlike, electronic buzzing sound that builds in volume and then tapers near the end. The sound is produced by rapidly vibrating muscles within tymbals, paired sound producing organs on the sides of each male’s abdomen. The resulting sound, often in excess of 120 decibels, can cause permanent human hearing damage if a calling cicada is close to a human ear. Interestingly, male cicadas can disable their own tympana, the equivalent of our ears, when calling.
Male calling is focused exclusively on attracting females. The mute females are limited to producing a series of clicks by flicking their wings. These efforts are aimed solely at assisting males in locating females. David Attenborough aptly shows the contrast between the male and female sounds in a related species, the seventeen year cicada (Magicicada septendecim), even simulating the impact of female clicking on a male in the link at the end of this entry.
There is an abundance of web-based information regarding cicadas. Sound recordings of cicadas and a variety of other singing insects can be readily accessed at InsectSingers.com. My favorite cicada-related resource is Cicada Mania. Despite its name, this professionally presented resource is an exceptional compilation of regularly updated information regarding numerous cicada species. The site, which provides top quality news, audio and video coverage, is international in scope. While examining one of Cicada Mania’s pages, I was particularly pleased to see that Illinois is slated as one of three U.S. states that should experience large-scale periodical cicada emergence in 2014. I’ve never experienced a massive emergence before, but plan to document as much as I can when it occurs!
Mass male chorusing occurs over a several week period, during which the short-lived, non-feeding adults emerge from underground. The dog day cicada life cycle takes three years, but because generations overlap, we can look forward to seeing, and HEARING them, each year.
If, like me, you live in the midwestern U.S., now is the time to get out and enjoy the short-lived sights and sounds of dog day cicadas. If you don’t have that opportunity, you can enjoy Attenborough’s video and demonstration.
Cicada emergence and subsequent calling and mating may not have the grandeur of celebrated natural events such as the annual migrations of sandhill cranes in the U.S. or wildebeest in Africa, but it is a phenomenal natural occurrence that we can eagerly anticipate and enjoy in our own backyards.