Dedicated to cicadas, the most amazing insects in the world.
Periodical cicada Brood XXI is extinct. It was a small brood of Magicicada with a 13-year lifecycle. It was last seen/heard in 1870. Visit Cicadas @ UCONN (formerly Magicicada.org) for more information.
Map from Marlatt, C.L.. 1907. The periodical cicada. Washington, D.C. : U.S. Dept. of Agriculture, Bureau of Entomology:
In recent years there have been quite a few articles & papers about declines in insect populations (see the list at the end of this article). Chances are you’ve seen one of these articles appear on Twitter or Facebook, or heard about it on TV, radio, podcasts, etc. I cannot vouch for the information in these articles, and I definitely cannot speak about topics like climate change or pesticides, as I lack the knowledge. I can talk about other pressures on cicada populations, and so I will.
Image: In the film Avengers: Infinity War, Thanos decimates half of all life in the Universe, including cicadas. In real life, depending on where you live, it’s likely that more than half of the cicadas have been eliminated.
Most cicadas are tree parasites. Reduce the number of trees, and you reduce the number of cicadas. It is a simple equation.
As you travel around your town, imagine all the places that there were once trees, and then imagine all the cicadas lost along with those trees.
Human beings (Homo sapiens) require a lot of space. We need space for our homes, schools, government buildings, the places we work, the places we play, places to grow our food & lumber, lands to mine for minerals, and the roads, rails, and airports that tie it all together. A lot of spaces that are now claimed by humanity were once home to cicadas (and other creatures).
The more we humans expand, the more cicada habitat contracts, and so the number of cicadas will naturally decline.
Invasive species — organisms introduced into a non-native habitat — pose a threat to cicadas by destroying cicada habitat. These include insects, worms, plants, or any other life form that weakens or kills trees, or otherwise disrupts cicada habitat. This USDA website is a good place to start to familiarize yourself with invasives.
One invasive species, in particular, that has without a doubt reduced cicada habitat in North America is the Emerald Ash Borer (EAB). EABs have killed millions of ash trees in North America. Each tree lost to EABs can represent the loss of thousands of cicadas, particularly Magicicada periodical cicadas.
The Spotted Lanternfly, native to Asia, is currently spreading in the eastern United States. It has become quite a menace in Pennsylvania, where it destroys trees and other plans. Most folks are concerned about its impact on agriculture, but I’m more concerned about its impact on ordinary trees outside of farms, where cicadas live. I’m also concerned that measures taken to fight the Spotted Lanternfly, might harm cicadas since they share the same suborder (Auchenorrhyncha) and similar biology.
One species of cicada and two broods of periodical cicadas went extinct over the past 150 years. Tibicen bermudiana went extinct in the 1950s due to a cedar blight. Brood XI Magicicadas were last recorded in 1954 in near the Ashford/Willington town line in eastern Connecticut. Brood XXI Magicicadas were last recorded in in 1870, in the Apalachicola River Valley in Florida. Given that new cicadas are discovered or described every year, it’s possible that other species of cicadas went extinct in recent times before there was time to discover or study them.
The next brood to go extinct is likely Brood VII. It has contracted over the years, and will likely only survive thanks to the Onondaga Nation reservation. Read the paper THE HISTORICAL CONTRACTION OF PERIODICAL CICADA BROOD VII (HEMIPTERA: CICADIDAE: MAGICICADA). by JOHN R. COOLEY, DAVID C. MARSHALL AND CHRIS SIMON. (J. New York Entomol. Soc. 112(2—3):198—204, 2004.) for more information.
I’ll likely expand and edit this article over time as I get more information on this topic. Feel free to pass only any information via the comments section of the article.
The Tibicen bermudiana Verrill (T. bermudianus) if you want the genus and species names to agree, and maybe now Neotibicen bermudianus) is a cicada that was endemic to Bermuda and is now extinct. Its closest relative is the Tibicen lyricen, which is found in the United States (and not extinct).
Here is a photo of a T. bermudiana from the collection found at the Staten Island Museum:
More photos by Roy Troutman, click for larger versions:
Tibicen bermudiana abdomen:
Tibicen bermudiana specimens:
A single specimen:
From the Bermuda’s Fauna website:
Sadly, when most of the Bermuda cedar trees were killed of by a blight in the 1950s, the cicadas that made the nights so uniquely magical and romantic in sound also largely disappeared.
Updated with a photo of the coin commemorating this cicada:
You might ask, “why were there once cicadas in my area, but now there are none?” There are a number of reasons why cicadas might die off in a particular area, or go totally extinct.
1) Destruction of host trees by a blight or destructive insect infestation. Tibicen bermudiana went extinct in the 1950s in Bermuda because of a cedar tree blight. Emerald Ash Borer insects are currently devastating Ash trees in North America. Ash trees are a favorite tree of Magicicada cassini, in particular.
2) Destruction of host trees by humans. Consider that every time a forest is removed to make room for another neighborhood, factory, strip mall, or highway, the cicadas that inhabited those areas died. Each time the human race expands, the cicadas must decline. The paper The Distribution of Brood Ten of the Periodical Cicadas in New Jersey in 1970 by John B. Schmitt documents the reduction of cicada populations in New Jersey, the nation’s most populous state. Also, the entire Brood XI went extinct in Connecticut as of 1954.
3) Extreme weather such as tornadoes, hurricanes, and flooding can destroy cicada habitat. While there are cases where cicadas were able to survive some pretty horrific weather, if trees are destroyed, or grasses that are hosts to young cicada nymphs are destroyed, or if floodwater sits too long, the cicadas are doomed.
4) Pesticides. It should be obvious that pesticides will kill cicadas.