Why another cicada website?
This website has been created to act as a repository for information regarding
annual and periodical cicadas found in the Mid-Atlantic area of the United
States. This area includes Delaware, Maryland, New Jersey, North Carolina,
Pennsylvania, Virginia, and West Virginia. Information such as life history
information, distributional information for each species, color photos of males
and females of each species, call files for each species, as well as calling
phenology and temperature ranges during calling have been collected for species
occurring in this geographic area. The purpose is to provide interested people,
students and teachers the needed resources to understand the distribution and
life histories of our local cicadas.
What is the difference between a periodical cicada and annual cicada?
Cicadas in our area can easily be divided into two groups according to when they
occur; those that appear every year (or annually) from the end of June to the
middle of October and those that do not appear every year, but occur every13 or
17 years (or periodically) generally from the middle of May to the middle of
June. There is also a difference in their appearance. Annual cicadas vary in
size from a ¼ of an inch to almost three inches in size. They tend to be black,
brown and green and have a green coloration along their wing margins. The
periodical cicadas are generally all black with red eyes and orange wing margins
and are generally an inch in length. Periodical and annual cicadas would rarely
occur at the same time. Some annual species can begin calling as early as
mid-June here in the Mid-Atlantic, however most species tend to call as
individuals and not the famous huge chorus that the periodicals are known for.
The annual cicadas would only begin to call after all the periodical cicadas
have died off.
What's a Brood?
A brood is a group or age class of periodical cicadas that emerge in the same
area during the same year. For the sake of tracking the emergences, Charles
Marlatt in 1907 designated roman numerals for each of the potential year classes
that could occur. He designated I (1) -XVII (17) for the seventeen year
periodical cicadas and XVIII (18) to XXX (30) for the thirteen year periodical
cicadas. However, there may not be a periodical cicada Brood emerging every
year. Over the last 100 years, researchers have documented the occurrence of 12
Broods of 17 year cicadas (I,II,III,IV,V,VI,VII,VIII,IX,X,XIII & XIV) and the
possible demise of Brood XI in Connecticut. (There is no Brood XII, XIII, XV,
XVI or XVII.) There are only 3 existing Broods of 13 year cicadas; XIX, XXII,
XXIII, the other ten don't exist.
Here in the Mid-Atlantic States, the picture has been somewhat clouded for a
number of reasons. One important reason is that periodical cicadas are not
always punctual. Some populations for various reasons emerge 4 years or 1 year
ahead of schedule. This can lead a great deal of confusion. There has also been
some mis-identification of periodical cicadas for early emerging annual cicadas.
Many authors over the past hundred years have also extrapolated the occurrences
back for many cycles of 17 years, based only on one record. These records have
been erroneously perpetuated through subsequent publications on a broods
historical range. In the southern portion of the Mid-Atlantic, many emergences
of Brood XIX of the 13 year cicadas were mistaken for 17 Year cicadas that were
emerging elsewhere in the Mid-Atlantic. This is one reason why different broods
have been reported from the tidewater area once and never reported again.
Website Layout
To locate information easier, this website has been divided into two basic
sections; periodical cicadas and annual cicadas. These sections are further
subdivided into individual species life histories, calling sound files and
timelines, temperature regimes, photos of males and females, and distribution
maps. Photos and sound files are currently not available for all species, but
research is ongoing to provide these.
CREDITS
A number of individuals have been instrumental in making it possible for me to accomplish my research goals. Through their contributions of time, knowledge and encouragement, I have increased my understanding of periodical and annual cicada species. I would like to recognize them for their contributions.
Gaye
Williams,
Entomologist, Maryland Department of Agriculture, Annapolis, MD
Who for many years has always been available for questions
and a great resource for information on periodical cicadas.
Dr. Thomas
Moore,
Professor Emeritus, University of Michigan, Ann Arbor, MI
Who has graciously supplied me with his outstanding
collection of periodical cicada locality records that he has accumulated over
the past 50 years.
Dr. David
Marshall,
Post Doc Graduate at the University of Connecticut, Storrs, CT
Who has tolerated countless hours of and e-mails with
questions regarding periodical cicada broods and their distribution. He and John
have always been available and encouraging in anything I was interested in
knowing or studying regarding cicadas. Their willingness to share their research
finding and methods has always surprised me.
Dr. John
Cooley,
Post Doc Graduate at the University of Connecticut, Storrs, CT
Who has also tolerated countless hours of and e-mails with
questions regarding periodical cicada broods and their distribution. He and Dave
have always been available and encouraging in anything I was interested in
knowing or studying regarding cicadas. Their willingness to share their research
finding and methods has always surprised me.
Dr. Alan
Sanborn,
Cicada Taxonomist, Barry University, Miami, FL
Who in my opinion is the leading expert on annual cicada
species in North America and has tolerated my less than desirable museum
specimen identification skills.