Editing Periodical cicadas (section)

==Broods==
Periodical cicadas are grouped into geographic [[wikt:brood|broods]] based on the calendar year when they emerge. For example, in 2014, the 13-year Brood XXII emerged in Louisiana and the 17-year Brood III emerged in western Illinois and eastern Iowa.

In 1907, [[Entomology|entomologist]] [[Charles Lester Marlatt]] assigned Roman numerals to 30 different broods of periodical cicadas: 17 distinct broods with a 17-year life cycle, to which he assigned brood numbers I through XVII (with emerging years 1893 through 1909); plus 13 broods with a 13-year cycle, to which he assigned brood numbers XVIII through XXX (1893 through 1905).<ref>{{cite book |last=Marlatt|first=C. L.|author-link=Charles Lester Marlatt|title=The Periodical Cicada|location=Washington, D.C.|edition=71|publisher=[[United States Department of Agriculture]], [[Bureau of Entomology]]: [[United States Government Publishing Office|Government Printing Office]]|year=1907|oclc=902809085|access-date=July 26, 2021|lccn=agr07001971|chapter-url=https://archive.org/details/periodicalcicada71marl/page/28/mode/1up|chapter=The Classification of the Broods|pages=28–30|url=https://archive.org/details/periodicalcicada71marl/page/n2/mode/1up|via=[[Internet Archive]]}}</ref> Marlatt noted that the 17-year broods are generally more northerly than are the 13-year broods.<ref name=Marlatt3>{{cite book|last=Marlatt|first=C.L|author-link=Charles Lester Marlatt|chapter-url=https://archive.org/details/periodicalcicada71marl/page/14/mode/1up|chapter=The Races, Broods, and Varieties of the Cicada: A Seventeen–Year Race and a Thirteen–Year Race|pages=14–18|url=https://archive.org/details/periodicalcicada71marl/page/n6/mode/1up|title=The Periodical Cicada|location=Washington, D.C.|edition=71|publisher=[[United States Department of Agriculture]], [[Bureau of Entomology]]: [[United States Government Publishing Office|Government Printing Office]]|year=1907|oclc=902809085|access-date=July 26, 2021|via=[[Internet Archive]]}}</ref>

Many of these hypothetical 30 broods have not been observed. Marlatt noted that some cicada populations (especially Brood XI in the valley of the [[Connecticut River]] in [[Massachusetts]] and [[Connecticut]]) were disappearing, a fact that he attributed to the reduction in forests and the introduction and proliferation of insect-eating "English sparrows" [[House sparrow|(House sparrows, ''Passer domesticus'')]] that had followed the European settlement of North America.<ref>{{cite book|last=Marlatt|first=C.L|author-link=Charles Lester Marlatt|chapter-url=https://archive.org/details/periodicalcicada71marl/page/13/mode/1up|chapter=Summary of the Habits and Characteristics of the Cicada.|pages=13–14|url=https://archive.org/details/periodicalcicada71marl/page/n6/mode/1up|title=The Periodical Cicada|location=Washington, D.C.|edition=71|publisher=[[United States Department of Agriculture]], [[Bureau of Entomology]]: [[United States Government Publishing Office|Government Printing Office]]|year=1907|oclc=902809085|access-date=July 26, 2021|via=[[Internet Archive]]}}</ref> Two of the broods that Marlatt named (Broods XI and XXI) have become extinct. His numbering scheme has been retained for convenience (and because it clearly separates 13- and 17-year life cycles), although only 15 broods are known to survive.<ref name=post>{{cite web |last=Post |first=Susan L. |title=A Trill of a Lifetime |url=http://www.inhs.uiuc.edu/highlights/periodicalCicada.html |year=2004 |publisher=The Illinois Steward|archive-url=https://web.archive.org/web/20070510060933/http://www.inhs.uiuc.edu/highlights/periodicalCicada.html |archive-date=10 May 2007}}</ref>
{|class="wikitable sortable" style="margin: 1em auto 1em auto; text-align:center;"
|-
! style="mifn-width: 68px;" |Name || style="mifn-width: 181px;" |Nickname || style="mifn-width: 60px;" |Cycle (yrs) || style="mifn-width: 101px;" |Last emergence || style="mifn-width: 101px;" |Next emergence || style="text-align:left;" class="unsortable" |Extent
|-
|{{sort|01|[[Brood I]]}} || Blue Ridge brood || 17 || 2012 || 2029 || style="text-align:left;" |Western Virginia, West Virginia
|-
|{{sort|02|[[Brood II]]}} || East Coast brood || 17 || 2013 || 2030 || style="text-align:left;" |Connecticut, Maryland, North Carolina, New Jersey, New York, Pennsylvania, Delaware, Virginia, District of Columbia
|-
|{{sort|03|[[Brood III]]}} || Iowan brood || 17 || 2014 || 2031 || style="text-align:left;" |Iowa
|-
|{{sort|04|[[Brood IV]]}} || Kansan brood || 17 || 2015 || 2032 || style="text-align:left;" |Eastern Nebraska, southwestern Iowa, eastern Kansas, western Missouri, Oklahoma, north Texas<ref>{{cite web|url=https://cicadas.uconn.edu/brood_04/|title=Brood IV|work=Cicadas|date=February 21, 2017|location=Storrs, Connecticut|publisher=University of Connecticut|access-date=July 25, 2021|archive-url=https://web.archive.org/web/20210421190926/https://cicadas.uconn.edu/brood_04/|archive-date=April 21, 2021|url-status=live}}</ref>
|-
|{{sort|05|[[Brood V]]}} || || 17 || 2016 || 2033 || style="text-align:left;" |Eastern Ohio, Western Maryland, Southwestern Pennsylvania, Northwestern Virginia, West Virginia, New York (Suffolk County)<ref>{{cite web|url=http://na.fs.fed.us/spfo/pubs/pest_al/cicada/cicada.htm|title=Periodical Cicada - Brood V|date=April 15, 2016|publisher=[[United States Department of Agriculture]]: [[United States Forest Service]]|archive-url=https://web.archive.org/web/20160407070945/http://na.fs.fed.us/spfo/pubs/pest_al/cicada/cicada.htm|archive-date=April 7, 2016}}</ref>
|-
|{{sort|06|[[Brood VI]]}} || || 17 || 2017 || 2034 || style="text-align:left;" |Northern Georgia, western North Carolina, northwestern South Carolina
|-
|{{sort|07|[[Brood VII]]}} || Onondaga brood || 17 || 2018 || 2035 || style="text-align:left;" |Central New York (Onondaga, Cayuga, Seneca, Ontario, Yates counties){{#tag:ref|Consists only of ''M.&nbsp;septendecim''|group=Note}}
|-
|{{sort|08|[[Brood VIII]]}} || || 17 || 2019 || 2036 || style="text-align:left;" |Eastern Ohio, western Pennsylvania, northern West Virginia
|-
|{{sort|09|[[Brood IX]]}} || || 17 || 2020 || 2037 || style="text-align:left;" |southwestern Virginia, southern West Virginia, western North Carolina
|-i
|{{sort|10|[[Brood X]]}} || Great eastern brood || 17 || 2021 || 2038 || style="text-align:left;" |New York, New Jersey, Pennsylvania, Delaware, Maryland, District of Columbia, Virginia, West Virginia, North Carolina, Georgia, Tennessee, Kentucky, Ohio, Indiana, Illinois, Michigan<ref>{{cite web|url=http://insects.ummz.lsa.umich.edu/fauna/Michigan_Cicadas/Periodical/BroodX.html|title=Brood X (17-year)| location=[[Ann Arbor, Michigan]]|publisher=Division of Insects: Museum of Zoology: [[College of Literature, Science, and the Arts|University of Michigan College of Literature, Science, and the Arts]]|archive-url=https://web.archive.org/web/20150927224643/http://insects.ummz.lsa.umich.edu/fauna/Michigan_Cicadas/Periodical/BroodX.html|access-date=March 13, 2024|archive-date=September 27, 2015|url-status=live}}</ref>{{#tag:ref|A premature emergence occurred in 2017.<ref>{{cite journal|last1=Sheikh|first1=Knvul|date=May 27, 2017|url=https://www.scientificamerican.com/article/brood-awakening-17-year-cicadas-emerge-4-years-early/ |title=Brood Awakening: 17-Year Cicadas Emerge 4 Years Early|journal=[[Scientific American]]|access-date=March 13, 2024|archive-url=https://web.archive.org/web/20240125171822/https://www.scientificamerican.com/article/brood-awakening-17-year-cicadas-emerge-4-years-early/|archive-date=January 25, 2024|url-status=live}}</ref>|group=Note}}
|-
|{{sort|11|[[Brood XI]]}} || || 17 || 1954 || {{N/a|Extinct}} || style="text-align:left;" |Connecticut, Massachusetts, Rhode Island. Last seen in 1954 in [[Ashford, Connecticut|Ashford]], Connecticut along the Fenton River
|-
|{{sort|13|[[Brood XIII]]}} || Northern Illinois brood || 17 || 2024 || 2041 || style="text-align:left;" |Northern Illinois and in parts of Iowa, Wisconsin, and Indiana{{#tag:ref|Reputedly has the largest emergence of cicadas by size known anywhere. A premature emergence occurred in 2020.<ref>{{cite web|last1=Schuster|first1=James|last2=Nixon|first2=Philip|url=https://extension.illinois.edu/insects/cicadas|title=Timed to perfection: Cicada's biological clock determines emergence|work=Insects: Cicadas|location=[[Urbana, Illinois]]|publisher=[[University of Illinois College of Agriculture, Consumer, and Environmental Sciences|University of Illinois Urbana-Champaign College of Agricultural, Consumer and Environmental Sciences]]: Illinois Extension|access-date=March 12, 2024|archive-url=https://web.archive.org/web/20240310005548/https://extension.illinois.edu/insects/cicadas|archive-date=March 10, 2024|url-status=live|quote=The northern Illinois brood, which will emerge in late May 2024, has a reputation for the largest emergence of cicadas known anywhere. This is due to the size of the emergence and the research and subsequent reporting over the years by entomologists Monte Lloyd and Henry Dybas at the [[Field Museum of Natural History|Field Museum]] in Chicago. During the 1956 emergence, they counted an average of 311 nymphal emergence holes per square yard of ground in a forested floodplain near Chicago. This translates to 1½ million cicadas per acre. In upland sites, they recorded 27 emergence holes per square yard, translating to about 133,000 per acre. This number is more typical of emergence numbers but is still a tremendous number of insects. .... 2020 {{!}} Northern Illinois Sub-Brood (part of Marlatt's XIII)}}</ref>|group=Note}}
|-
|{{sort|14|[[Brood XIV]]}} || || 17 || 2008 || 2025 || style="text-align:left;" |Southern Ohio, Kentucky, Tennessee, Massachusetts, Maryland, North Carolina, Pennsylvania, northern Georgia, Southwestern Virginia and West Virginia, and parts of New York and New Jersey
|-
|{{sort|19|[[Brood XIX]]}} || Great Southern Brood || 13 || 2024 || 2037 || style="text-align:left;" |Alabama, Arkansas, Georgia, Indiana, Illinois, Kentucky, Louisiana, Maryland, Missouri, Mississippi, North Carolina, Oklahoma, South Carolina, Tennessee, and Virginia{{#tag:ref|Arguably the largest (by geographic extent) of all periodical cicada broods.<ref>{{cite web|url=https://cicadas.uconn.edu/brood_19/|title=Brood XIX: The Great Southern Brood|work=Biodiversity Research Collections: Periodical Cicada Information Pages|date=February 21, 2017 |location=Storrs, Connecticut|publisher=University of Connecticut|access-date=March 13, 2024|language=en-US|archive-url=https://web.archive.org/web/20240224013749/https://cicadas.uconn.edu/brood_19/|archive-date=February 24, 2024|url-status=live|quote=Brood XIX is arguably the largest (by geographic extent) of all periodical cicada broods, with records along the east coast from Maryland to Georgia and in the Midwest from Iowa to Oklahoma.}}</ref>|group=Note}}
|-
|{{sort|21|Brood XXI}} || Floridian Brood || 13 || 1870 || {{N/a|Extinct}} || style="text-align:left;" |Last recorded in 1870, historical range included the Florida panhandle<ref>{{cite book |last=Marlatt |first=C.L. |title=The Periodical Cicada|url=https://archive.org/details/periodicalcicada71marl/page/n6/mode/1up|location=Washington, D.C.|edition=71|publisher=[[United States Department of Agriculture]], [[Bureau of Entomology]]: [[United States Government Publishing Office|Government Printing Office]]|year=1907|oclc=902809085|access-date=July 26, 2021|via=[[Internet Archive]] |author-link=Charles Lester Marlatt}}</ref>
|-
|{{sort|22|[[Brood XXII]]}} || Baton Rouge Brood<ref name=broodXXII>{{cite web|title=Brood XXII (13-year) The Baton Rouge Brood|url=http://www.magicicada.org/about/brood_pages/broodXXII.php|publisher=National Geographic Society|access-date=28 August 2011|archive-url=https://web.archive.org/web/20110903070654/http://www.magicicada.org/about/brood_pages/broodXXII.php|archive-date=3 September 2011|url-status=live}}</ref> || 13 || 2014 || 2027 || style="text-align:left;" |Louisiana, Mississippi{{#tag:ref|This 13-year brood does not include ''M.&nbsp;neotredecim''.|group=Note}}
|-
|{{sort|23|[[Brood XXIII]]}} || Mississippi Valley Brood<ref>{{cite web|url=https://cicadas.uconn.edu/brood_23/|access-date=24 Feb 2022|date=Feb 2021|title=Brood XXIII}}</ref> || 13 || 2015 || 2028 || style="text-align:left;" |Arkansas, Illinois, Indiana, Kentucky, Louisiana, Missouri, Mississippi, Tennessee
|- class="sortbottom"
|colspan="6" style="text-align:left;"|
{{Reflist|group=Note}}
|}

Periodical cicadas that emerge outside the expected time frame are called stragglers. Although they can emerge at any time, they usually do so one or four years before or after most other members of their broods emerge.<ref>{{cite web|url=https://cicadas.uconn.edu/stragglers/|title=Stragglers|work=Biodiversity Research Collections: Periodical Cicada Information Pages|date=January 25, 2021 |location=Storrs, Connecticut|publisher=University of Connecticut|access-date=March 13, 2024|language=en-US|archive-url=https://web.archive.org/web/20240226160405/https://cicadas.uconn.edu/stragglers/|archive-date=February 26, 2024|url-status=live}}</ref> Stragglers with a 17-year life cycle typically emerge four years early. Those with a 13-year cycle typically emerge four years late.<ref>{{cite web|url=https://www.cicadamania.com/cicadas/what-are-stragglers/|title=What are stragglers?|work=Cicada Mania|date=June 27, 2015|access-date=March 13, 2024|archive-url=https://web.archive.org/web/20240308044747/https://www.cicadamania.com/cicadas/what-are-stragglers/|archive-date=March 8, 2024|url-status=live|quote=Typically cicadas with a 17-year life cycle will emerge 4 years early, and cicadas with a 13-year cycle will emerge 4 years late.}}</ref> The emergence of stragglers may in theory be indicative of a brood shifting from a 17-year cycle to a 13-year one.<ref>{{cite news |url=https://www.economist.com/science-and-technology/2024/05/28/hordes-of-cicadas-are-emerging-simultaneously-in-america |title=Hordes of cicadas are emerging simultaneously in America |newspaper=The Economist |date=May 28, 2024 |access-date=May 29, 2024}}</ref>

Brood XIII of the 17-year cicada, which reputably has the largest emergence of cicadas by size known anywhere, and Brood XIX of the 13-year cicada, arguably the largest (by geographic extent) of all periodical cicada broods, were expected to emerge together in 2024 for the first time since 1803. However, the two broods were not expected to overlap except potentially in a thin area in central and eastern Illinois ([[Macon County, Illinois|Macon]], [[Sangamon County, Illinois|Sangamon]], [[Livingston County, Illinois|Livingston]], and [[Logan County, Illinois|Logan]] counties).<ref>Multiple sources:
* {{cite web|url=https://www.cicadamania.com/cicadas/2024-cicada-forecast/|title=2024 Cicada Forecast|date=February 10, 2024|work=Cicada Mania|access-date=March 13, 2024|archive-url=https://web.archive.org/web/20240308050919/https://www.cicadamania.com/cicadas/2024-cicada-forecast/|archive-date=March 8, 2024|url-status=live|quote=Both Brood XIX and XIII exist in Macon, Sangamon, Livingston and Logan counties in Illinois. The easily accessible place they come closest to overlapping is Springfield, Illinois, which is in Sangamon County.}}
* {{cite web|last1=Schuster|first1=James|last2=Nixon|first2=Philip|url=https://extension.illinois.edu/insects/cicadas|title=Timed to perfection: Cicada's biological clock determines emergence|work=Insects: Cicadas|location=[[Urbana, Illinois]]|publisher=[[University of Illinois College of Agriculture, Consumer, and Environmental Sciences|University of Illinois Urbana-Champaign College of Agricultural, Consumer and Environmental Sciences]]: Illinois Extension|access-date=March 12, 2024|archive-url=https://web.archive.org/web/20240310005548/https://extension.illinois.edu/insects/cicadas|archive-date=March 10, 2024|url-status=live|quote=The northern Illinois brood, which will emerge in late May 2024, has a reputation for the largest emergence of cicadas known anywhere. This is due to the size of the emergence and the research and subsequent reporting over the years by entomologists Monte Lloyd and Henry Dybas at the [[Field Museum of Natural History|Field Museum]] in Chicago. During the 1956 emergence, they counted an average of 311 nymphal emergence holes per square yard of ground in a forested floodplain near Chicago. This translates to 1½ million cicadas per acre. In upland sites, they recorded 27 emergence holes per square yard, translating to about 133,000 per acre. This number is more typical of emergence numbers but is still a tremendous number of insects.}}
* {{cite web|url=https://cicadas.uconn.edu/|title=The 2024 Periodical Cicada Emergence|work=Biodiversity Research Collections: Periodical Cicada Information Pages|location=Storrs, Connecticut|publisher=University of Connecticut|access-date=March 13, 2024|language=en-US|archive-url=https://web.archive.org/web/20240312062005/https://cicadas.uconn.edu/|archive-date=March 12, 2024|url-status=live|quote=In 2024, 13-year Brood XIX, which is the largest of all periodical cicada broods, will co-emerge with 17-year Brood XIII; these two broods are adjacent (but not significantly overlapping) in north-central Illinois.}}
* {{cite web|url=https://cicadas.uconn.edu/brood_19/|title=Brood XIX: The Great Southern Brood|work=Biodiversity Research Collections: Periodical Cicada Information Pages|date=February 21, 2017 |location=Storrs, Connecticut|publisher=University of Connecticut|access-date=March 13, 2024|language=en-US|archive-url=https://web.archive.org/web/20240224013749/https://cicadas.uconn.edu/brood_19/|archive-date=February 24, 2024|url-status=live|quote=Brood XIX is arguably the largest (by geographic extent) of all periodical cicada broods, with records along the east coast from Maryland to Georgia and in the Midwest from Iowa to Oklahoma.}}</ref> The next such dual emergence of these two particular broods will occur in 2245, 221 years after 2024. Many other 13-year and 17-year broods emerge during the same years, but the broods are not geographically close.<ref>Multiple sources:
* {{cite web |first=Aimee|last=Ortiz|date=January 19, 2024|url=https://www.nytimes.com/2024/01/19/science/cicadas-emergence-broods.html |title=The World Hasn't Seen Cicadas Like This Since 1803 |work=[[The New York Times]]|access-date=March 13, 2024|archive-url=https://web.archive.org/web/20240309104954/https://www.nytimes.com/2024/01/19/science/cicadas-emergence-broods.html|archive-date=March 9, 2024|url-status=dead|quote=Brood XIX and Brood XIII will both emerge this spring. The last time these bugs showed up at the same time in the United States, Thomas Jefferson was president. After this spring, it’ll be another 221 years before the broods, which are geographically adjacent, appear together again.}}
* {{cite news|first=Carys|last=Matthews|date=May 29, 2024|url=https://www.livescience.com/animals/insects/cicada-double-brood-event-what-to-expect-when-trillions-of-bugs-emerge-in-eastern-us|title=Cicada double brood event: What to expect as trillions of bugs emerge in Eastern US|work=[[Live Science]]|access-date=September 1, 2024|archive-url=https://web.archive.org/web/20240629230225/https://www.livescience.com/animals/insects/cicada-double-brood-event-what-to-expect-when-trillions-of-bugs-emerge-in-eastern-us|archive-date=June 29, 2024|url-status=live|quote="Billions, even trillions, of cicadas are going to emerge at the same time across 17 states,” Chris Simon, a professor at UConn’s Department of Ecology and Evolutionary Biology and one of the scientists who runs the database told Life Science. ... Despite the huge volumes of insects set to emerge, the co-emergence of Brood XIII and XIX likely won't look much different from other periodical cicada emergences. That's because, for the most part, they won't emerge from the same locations. There's only a small woodland area in Springfield, Illinois, where the two broods may co-emerge. "The broods won't overlap significantly due to the latitudinal spread involved," John Cooley, founder of the Periodical Cicada Project and a professor in UConn's Department of Ecology and Evolutionary Biology, told Live Science.  .... It is a rare occurrence for two specific periodical broods of different life cycles to emerge at the same time and overrlap in location. "The co-emergence of any two broods of different cycles is rare, because the cycles are both prime numbers,” Cooley said. "Any given 13- and 17-year broods will only co-emerge once every 13 x 17 = 221 years." Despite their geographic proximity, the two broods have not emerged at the same time for 221 years, although many other 13-year and 17-year broods have appeared in the same year. "2015 was the last time a 13-year brood emerged with a 17-year brood, when Brood XXIII emerged with Brood IV. However, the two broods weren't geographically close," Simon told Live Science. "Similarly, adjacent Brood IV and Brood XIX both appeared in 1998 but, again, weren't close."}}</ref>
 
===Map of brood locations===
[[File:Periodical Cicada Broods of the United States.png|alt=County-by-county map showing the locations of cicada broods, published May 2013|none|thumb|800px|USDA Forest Service map of periodical cicada brood locations by county and timing of next emergence (as of 2024)]]