Brood XIX (also known as The Great Southern Brood) is the largest (most widely distributed) brood of 13-year periodical cicadas, last seen in 2024 across a wide stretch of the southeastern United States. Periodical cicadas (Magicicada spp.) are often referred to as "17-year locusts" because most of the known distinct broods have a 17-year life cycle. Brood XIX is one of only three surviving broods with a 13-year cycle. It is also notable because it includes four different 13-year species, one of which was discovered in Brood XIX in 1998 by scientists listening to cicada songs.
In 1907, entomologist C. L. Marlatt postulated the existence of 30 different broods of periodical cicadas: 17 distinct broods with a 17-year life cycle, to which he assigned Roman numerals I through XVII (with emerging years 1893 through 1909); plus 13 broods with a 13-year cycle, to which he assigned Roman numerals XVIII through XXX (1893 through 1905). [1] Many of these hypothetical broods, however, have not been observed. Today only 15 are recognized. [2]
Brood XIX is one of three extant broods of 13-year cicadas. The other two are Broods XXII and XXIII, expected to re-emerge in 2027 and 2028 respectively. [3] A fourth 13-year brood, Brood XXI (The Floridian Brood) was last recorded in 1870 in the Florida panhandle, but is believed to be now extinct. [4]
Brood XIX includes all four different species of 13-year cicadas: Magicicada tredecim (Walsh and Riley, 1868), Magicicada tredecassini (Alexander and Moore, 1962), Magicicada tredecula (Alexander and Moore, 1962), and the recently discovered Magicicada neotredecim (Marshall and Cooley, 2000). 2011 was the first appearance of Brood XIX since the discovery of the new species, which was first observed in this brood in 1998 when scientists observed an unexpected peak of acoustical frequencies in the brood's song. [5] [6]
The two species M. tredecim and M. neotredecim have an unusual geographical relationship in Brood XIX, with only a slight overlap between them, in a narrow band from northern Arkansas to southern Indiana. The other 13-year species occur together throughout the brood range, so in most parts of the range only three of the four species are present. [7] All four 13-year species have distinct male calling songs, but the songs of M. tredecim and M. neotredecim in their narrow range of overlap show reproductive character displacement (RCD) that makes them even more distinct. (RCD functions to prevent reproductive overlap.) [6] RCD is particularly noticeable in Brood XIX. [8]
For Brood XIX in Alabama, adults of M. tredecula are less common than those of M. tredecim and M. tredecassini. [9]
Most maps of cicada distribution originate from 19th-century compilations that may show ranges much wider than those of current broods. The National Geographic Society is gathering reports from the public about the geographical distribution of Brood XIX as part of a larger project to remap the distribution of Magicicada. [10] Older maps show occurrences of Brood XIX cicadas in Missouri, Arkansas, Louisiana, Mississippi, Tennessee, Kentucky, Indiana, Virginia, North Carolina, South Carolina, and Georgia. [5]
Across most of the range of Brood XIX, one observes M. tredecim in the southern regions and M. neotredecim in more northern ones, with some overlap in the westernmost region (mostly Missouri and Illinois). [6]
In early May 2011, cicadas began emerging throughout an area roughly enclosed by Georgia, Texas, Alabama, North Carolina, Missouri, and Tennessee. The next two appearances will be in 2037 and 2050. [11]
News reports of the cicadas' emergence in Illinois included links to a video showing holes in the ground left by larval emergence, an adult cicada breaking out of its larval shell, and massed adult cicadas marching up tree trunks. [12]
By June 8, 2011, a North Carolina newspaper reported that adult cicadas, which typically live for about a month, were dying en masse. Nymphs from eggs that have been laid by Brood XIX females emerged from the earth again in 2024, restarting the cycle. [13]
Brood XIX of the 13-year cicada, arguably the largest (by geographic extent) of all periodical cicada broods, and Brood XIII of the 17-year cicada, which reputably has the largest emergence of cicadas by size known anywhere, emerged together in 2024 for the first time since 1803. However, the two broods did not overlap except in a thin area in central and eastern Illinois (Macon, Sangamon, Livingston, and Logan counties). Therefore, the density of cicadas in most areas were the same as usual. [14] The next such dual emergence of Brood XIX and Brood XIII is expected to occur in 2245, 221 years after 2024, [15] but after 2024, the next eight successive emergences of Brood XIX will be dual emergences, with eight different 17-year Broods—in 2024 (with Brood XIII), 2037 (Brood IX), 2050 (Brood V), 2063 (Brood I), 2076 (Brood XIV), 2089 (Brood X), 2102 (Brood VI), and 2115 (Brood II)—so it will not be until 2128 that Brood XIX will be the only Brood emerging that year.
The cicadas are a superfamily, the Cicadoidea, of insects in the order Hemiptera. They are in the suborder Auchenorrhyncha, along with smaller jumping bugs such as leafhoppers and froghoppers. The superfamily is divided into two families, the Tettigarctidae, with two species in Australia, and the Cicadidae, with more than 3,000 species described from around the world; many species remain undescribed. Nearly all of cicada species are annual cicadas with the exception of the few North American periodical cicada species, genus Magicicada, which in a given region emerge en masse every 13 or 17 years.
Brood X, the Great Eastern Brood, is one of 15 broods of periodical cicadas that appear regularly throughout the eastern United States. The brood's first major emergence after 2021 is predicted to occur during 2038.
The term periodical cicada is commonly used to refer to any of the seven species of the genus Magicicada of eastern North America, the 13- and 17-year cicadas. They are called periodical because nearly all individuals in a local population are developmentally synchronized and emerge in the same year. Although they are sometimes called "locusts", this is a misnomer, as cicadas belong to the taxonomic order Hemiptera, suborder Auchenorrhyncha, while locusts are grasshoppers belonging to the order Orthoptera. Magicicada belongs to the cicada tribe Lamotialnini, a group of genera with representatives in Australia, Africa, and Asia, as well as the Americas.
Charles Lester Marlatt was an American entomologist who worked in the Bureau of Entomology of the US department of agriculture. He was involved in the creation of Plant Quarantine Act, applications of classical biological control, and recorded the emergence of broods of periodical cicadas across the United States. He also specialized on the systematics of the Tenthredinidae.
Brood XIII is one of 15 separate broods of periodical cicadas that appear regularly throughout the midwestern United States. Every 17 years, Brood XIII tunnels en masse to the surface of the ground, mates, lays eggs in tree twigs, and then dies off over several weeks.
Magicicada cassini, known as the 17-year cicada, Cassin's periodical cicada or the dwarf periodical cicada, is a species of periodical cicada. It is endemic to North America. It has a 17-year life cycle but is otherwise indistinguishable from the 13-year periodical cicada Magicicada tredecassini. The two species are usually discussed together as "cassini periodical cicadas" or "cassini-type periodical cicadas." Unlike other periodical cicadas, cassini-type males may synchronize their courting behavior so that tens of thousands of males sing and fly in unison. The species was first reported to the Academy of Natural Sciences of Philadelphia by Margaretta Morris in 1846. In 1852, the species was formally described by J. C. Fisher and given the specific name cassini in honour of John Cassin, an American ornithologist, whose own report was included by Fisher in his publication.
Magicicada septendecim, sometimes called the Pharaoh cicada or the 17-year locust, is native to Canada and the United States and is the largest and most northern species of periodical cicada with a 17-year lifecycle.
Massospora cicadina is a fungal pathogen that infects only 13 and 17 year periodical cicadas. Infection results in a "plug" of spores that replaces the end of the cicada's abdomen while it is still alive, leading to infertility, disease transmission, and eventual death of the cicada.
Brood XIV is one of 15 separate broods of periodical cicadas that appear regularly throughout parts of the midwestern, northeastern, and southeastern United States. Every 17 years, the cicadas of Brood XIV tunnel en masse to the surface of the ground, mate, lay eggs, and then die off in several weeks.
Magicicada neotredecim is the most recently discovered species of periodical cicada. Like all Magicicada species, M. neotredecim has reddish eyes and wing veins and a black dorsal thorax. It has a 13-year life cycle but seems to be most closely related to the 17-year species Magicicada septendecim. Both species are distinguished by broad orange stripes on the abdomen and a unique high-pitched song said to resemble someone calling "weeeee-whoa" or "Pharaoh." They differ only in life cycle length.
Magicicada tredecim is a 13-year species of periodical cicada, closely related to the newly discovered 13-year species Magicicada neotredecim, from which it differs in male song pitch, female song pitch preferences, abdomen color, and mitochondrial DNA. Both M. tredecim and M. neotredecim are closely related to the 17-year species M. septendecim, which was identified by Linnaeus in 1758; these three species are often grouped together under the name decim periodical cicadas.
Decim periodical cicadas is a term used to group three closely related species of periodical cicadas: Magicicada septendecim, Magicicada tredecim, and Magicicada neotredecim. M. septendecim, first described by Carl Linnaeus, has a 17-year life cycle; the name septendecim is Latin for 17. M. tredecim, first described in 1868, has a similar call and appearance but a 13-year life cycle; tredecim is Latin for 13. M. neotredecim, first described in 2000 by Marshall and Cooley in an article in the journal Evolution, is a 13-year species but otherwise much more similar to M. septendecim than to M. tredecim as shown by studies of DNA and abdominal color variation by Chris Simon and colleagues in a companion article in the same journal issue.
David Rothenberg is a professor of philosophy and music at the New Jersey Institute of Technology, with a special interest in animal sounds as music. He is also a composer and jazz musician whose books and recordings reflect a longtime interest in understanding other species such as singing insects by making music with them.
The Cassini periodical cicadas are a pair of closely related species of periodical cicadas: Magicicada cassini, having a 17-year life cycle, and Magicicada tredecassini, a nearly identical species with a 13-year life cycle.
Brood II is one of 15 separate broods of Magicicada that appear regularly throughout the northeastern United States. Every 17 years, Brood II tunnels en masse to the surface of the ground, mates, lays eggs, and then dies off over the span of several weeks.
Brood XXII is a brood of 13-year periodical cicadas, last seen in 2014 in a geographic region centered on Baton Rouge, Louisiana, as well as other locations in southeast Louisiana and southwest Mississippi. Periodical cicadas are often referred to as "17-year locusts" because most of the known distinct broods have a 17-year life cycle. Brood XXII is one of only three surviving broods with a 13-year cycle. The next emergence of The Baton Rouge Brood is expected in 2027.
Brood XI was a brood of periodical cicadas that appeared regularly in the eastern United States. It was one of the smallest 17-year broods, consisting exclusively of the species Magicicada septendecim, and was historically restricted to areas of Connecticut, Massachusetts, and Rhode Island which appeared to be at the northern limit of the species' range. Brood XI has not been seen since its 1954 emergence and is now generally regarded as extinct.
Brood V is one of twelve extant broods of periodical cicadas that emerge as adults once every 17 years in North America. They are expected to appear in the eastern half of Ohio, the southwestern corner of Pennsylvania, the upper two-thirds of West Virginia less the Eastern Panhandle, far western Maryland, and some places in Virginia abutting West Virginia. Also included in Brood V is a population that emerges in Suffolk County, Long Island, New York. They last emerged in 2016, and their next appearance will be in 2033.
Brood IX, is one of 15 broods of periodical cicadas that appear regularly throughout the United States in 13 or 17-year intervals. Seventeen-year Brood IX is concentrated in Virginia, West Virginia, and North Carolina.
Brood XXIII is a brood of 13-year periodical cicadas that last emerged in 2015 around the Mississippi River in the states of Louisiana, Mississippi, Arkansas, Tennessee, Missouri, Kentucky, and Illinois. The brood was also seen in Southwestern Indiana and Western Kentucky around the Ohio River, and as far north as Weldon Springs State Park in DeWitt County, Illinois. Brood XXIII is one of three extant periodical cicada broods with a 13-year life cycle, and thus is expected to be seen again in 2028.
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.
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 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.
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.
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.
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.