Summer would not be complete without the sounds of cicadas. Annual cicadas provide us with sonic entertainment each summer. Periodical cicadas reward our patience with their virtuoso wall of sound every 13 or 17 years, depending on the species.
Our local annual cicada species can be tricky to tell apart from each other by their appearance. They are all a bit less than two inches long and mottled dark green, black and brown. Luckily, a few of them can be identified by the tunes they sing. Technically they are not singing, but vibrating a specialized part of their exoskeleton called a tymbal.
The Dog Day Cicada (Tibicen canicularis) is abundant in this area. The common name “Dog Day Cicada” is often used for all annual cicadas, but that’s not fair to the other species. “Canicularis” is the Latin word for “little dog”. Thus, annual cicadas associated with the “dog days” of summer. The Dog Day Cicada sounds a bit like a high pitched metallic buzz saw, with no rhythmic rattling to it.
The Swamp Cicada (Tibicen tibicen) is also called the Morning Cicada because it is the only one you are likely to hear before noon. The call of this species has some rattle to it. The sound reminds me of a rapidly shaken maraca or a very fast lawn sprinkler. Despite its name, the Swamp Cicada is more likely to be found singing above a tree-lined street than above an actual swamp.
Linne’s Cicada (Tibicen linnei) was named after the Swedish biologist, Carl Linnaeus. Back in the 1700’s he popularized the idea of assigning those cryptic scientific names to organisms. Linne’s Cicada’s rattle-like call sounds a bit like the Swamp Cicada, but it is most active in the afternoon and evening
The Lyric Cicada (Tibicen lyricen) is also found in this region. The call of the Lyric Cicada is longer and not as rattle-like as Linne’s Cicada. It reminds me of another sound of summer; the music of baseball cards in the spokes of a bicycle wheel.
You will never hear our cicadas after dark. Similar night sounds could be crickets, katydids, frogs or your neighbor’s air conditioning unit.
It may sound funny that the easiest way to identify our local cicadas is by their sound. This trick is used by bird watchers all the time. It lets them “see” birds when they are not visible. A great way to get a really close look at cicadas was invented by Dr. Chuck Holliday. Sit next to a Cicada Killer Wasp nest and wait for them bring the cicadas to you. Brilliant!
Annual cicadas are actually around 3-5 years old by the time we hear them. They have spent their whole larva-hoods sucking plant fluids from tree roots. Adult cicadas only live for a few weeks. They sip fluids from trees and spend a great deal of time trying to find an ideal partner.
If you find the singing of cicadas to be annoying, make sure you only blame the males. The females are practically silent… other than a few endearing clicks she makes with her wings when she finds a male that she finds to be the cat’s pajamas. The males buzz in order to attract females. It seems to work for them.
Towards the end of summer female cicadas will lay their eggs in narrow tree branches. After a few weeks, tiny cicada larvae will drop to the ground and burrow into the soil in search of a tree root. Once they tap into a tasty root, they will hang out underground for several years before seeing the light of day again.
Some people call cicadas locusts. Cicadas are not locusts at all. Locusts are a type of grasshopper. Cicadas are more closely related to aphids than they are to locusts. However, like locusts, sautéed cicadas (aka "sky lobsters") are a summer treat in many of the trendier parts of the world.
Periodical cicadas (Magicicada spp.) are the ones that are black, have red eyes and occasionally appear by the zillions in the very early summer (before the annual cicadas have started to do their thing). In this region, periodical cicadas famously emerge every 17 years. They typically show up in such vast numbers that predators like birds and dogs simply cannot possibly eat enough of them to make any real difference to the size of the population.
The periodical cicadas that emerge as adults in a particular year are lumped into “broods”. Each brood is assigned a number that corresponds to the year that the cicadas emerge. For the most part, the regions that the periodical cicada broods occupy do not overlap with each other. Thus, in any given region, there is generally only one brood of resident cicadas. People in that region will only see periodical cicadas once every 17 years.
The last time we heard periodical cicadas anywhere near the Lehigh Valley was Brood XIV back in 2008. They were especially abundant near the center of the state. Many readers will remember our famous 2004 Brood X periodical cicada emergence. Some with mixed emotions. The noise of periodical cicadas can exceed that of a lawnmower. They still pose less of a risk for permanent hearing loss than a Justin Bieber concert.
Residents of Allentown did not get much of a periodical cicada show back in 2004, but a quick drive south would have put you in the audience of an amazing chorus.
Next summer, Brood II periodical cicadas will be making their cameo in some parts of Eastern Pennsylvania. There are no historical records of this brood in Lehigh County. That doesn’t mean they weren’t here back in 1996 or 1979 or 1962 and so on, just that nobody reported them to the authorities.
I am looking forward to participating in a project next summer to precisely map where Brood II periodical cicadas emerge in Eastern Pennsylvania. This way we can tell if their populations are actually growing or shrinking the next time we check in 2030. Can’t wait! This will be the topic of an upcoming blog, since it is so cool and will involve a public reporting component.
Cicadas are very easy to control. Simply remove all of the trees on your area and replace them with pavement. Another effective control strategy is to make your garden more attractive to Cicada Killer Wasps. My favorite approach is to enjoy them. They serve as an audible reminder to squeeze the very most out of our all too short summer season.
This work by Marten Edwards is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.