Massospora cicadina | |
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Magicicada sp. infected with Massospora cicadina. Note the spore mass that has replaced the abdomen of the cicada. | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Fungi |
Division: | Entomophthoromycota |
Class: | Entomophthoromycetes |
Order: | Entomophthorales |
Family: | Entomophthoraceae |
Genus: | Massospora |
Species: | M. cicadina |
Binomial name | |
Massospora cicadina | |
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.
M. cicadina belongs to the phylum Zoopagomycota, subphylum Entomophthoromycota, and order Entomophthorales. About a dozen other species of Massospora are known, each of which attacks a specific species of cicada.[ citation needed ]
In 1845, John H. B. Latrobe read a memoir of Benjamin Banneker at a meeting of the Maryland Historical Society. Latrobe reported that Banneker had in April 1800 described in his record book some of the characteristics of the periodical cicada, whose Brood X would soon begin emerging where he lived. In his description, Banneker wrote that the insects:
... begin to Sing or make a noise from first they come out of the Earth till they die. The hindermost part rots off, and it does not appear to be any pain to them, for they still continue on Singing till they die. [1]
In 1851, Joseph Leidy described and illustrated the fungus that had apparently caused the abdominal "rot" that Banneker had observed. [2] [3] [4] In 1879, Charles Horton Peck described the fungus and named it Massospora cicadina. [2] [4] [5] Peck placed the fungus among the class Coniomycetes, but in 1888 Thaxter and Forbes placed it instead in Entomophthoraceae. It was not until 1921 that the pathogen's microscopic characteristics were thoroughly studied by Speare, [6] who found that conidia germinate quickly when placed in a nutrient substance. [7]
M. cicadina infects Magicicada species, which are 13- and 17-year periodical cicadas. Magicicada species spend most of their lives underground as nymphs, feeding on xylem fluids of tree roots. [8] They dig upwards through the soil to molt into adults and emerge above ground after 13 or 17 years. Adult periodical cicadas live only for 4 to 6 weeks, to mate and deposit their eggs. Females attract males for mating by flicking their wings, while males produce a mating call. After mating, female cicadas deposit up to 600 or more eggs in V-shaped cuts on tree twigs (usually 20 eggs at a time in each cut). [8]
This image shows the confirmed and possible modes of transmission for cicadas infected with M. cicadina. Red lines represent an infected cicada, and black lines correspond to a healthy cicada. (Dashed lines show incubation periods for both the cicada and the fungus.) The question marks denote other possible routes of transmission.
Spores of M. cicadina are capable of germinating and infecting cicadas at as little as one year but may remain dormant for either 13 or 17 years before becoming active. This synchronous cycle corresponds with local periods of cicada emergence. M. cicadina is thought to be the only pathogen that coincides with its host's 17-year life cycle; because of this it is considered to have the longest life cycle of any known fungus. [9] [10]
M. cicadina resting spores do not require a dormant period: they are capable of germinating and infecting periodical cicadas after less than a year from their introduction into soil. Cicadas are believed to become infected by fungal spores as the nymphs dig tunnels to the soil surface days before their emergence as adults. [10] [11]
The Initial infection takes place while cicada nymphs dig their way to the surface of the soil before emerging as adults. [10] [11] It is presumed that the emerging cicadas are infected by resting spores they encounter in the soil. In early stages of infection, hyphal bodies of the fungus are found in the host tissues. Later, Stage I infected adult cicadas produce haploid conidia, forming the asexual stage of the fungus. [9] Conidia produced by Stage I infected cicadas are capable of infecting other adult cicadas.
There is no difference between the proportion of male to female nymphs being infected by spores in this stage. [12] In the early stages of Stage I infection, the infection is completely concealed inside the abdomen of the cicada. Some time before the death of the host, the rear segments of the abdomen fall off, revealing a white, chalky mass or "plug" of the fungus, which produces spores. Because of this method of spreading of Stage I spores, cicadas infected with M. cicadina have been referred to as "flying salt shakers of death". Infected cicadas are infertile.
Stage I infected cicadas are observed to spend more time walking around and dragging their abdomen, which may aid in spreading conidia that infect other cicadas. This behavioral change is thought to be the result of a fungal extended phenotype, the physical afflictions of the infected cicadas, or the general phenology of cicada life cycles. [10] Progression in male and female cicadas is similar, including the time elapsed before the abdominal segments fall off. [12]
Stage I infected males respond to mating calls of both males and females and attract healthy males through flicking their wings, a behavior only observed in healthy females. This altered behavior aids in infection of healthy cicadas. [10] Stage I infected males also tolerate mounting from courting males, suggesting that M. cicadina alters insect sexual behavior to increase infection rates. [9] The fruiting bodies of M. cicadina on Stage I infected adult cicadas contain a substituted amphetamine alkaloid, cathinone. [13]
Cicadas that come into contact with conidia from an infected adult cicada contract Stage II infection. During Stage II infection, the fungus produces a different kind of spore: resting spores that have thick walls and are not directly infectious to adult cicadas. Instead, the resting spores lie dormant in soil and will infect the next generation of cicadas during their next 13 or 17 year emergence from the soil. [6]
The fungus renders both males and females sterile, though the insect may remain alive and mobile while discharging spores. Infected cicadas display some normal behavior such as sexual responsiveness, and even copulation between infected and healthy cicadas has been observed. [6] As cicada males form large chorus centers during mating, the infection rate of males with the resting spore stage is typically higher than infected females at this stage. [9] Conidia that fill the abdomens of infected males at this stage also alter the pitch of their mating call, resulting in them sounding smaller than they actually are to females, which may also contribute to the prevalence of higher infection rates in males than in females. [9]
Species of the genus Massospora are found in the same habitats as their host cicadas, which includes large temperate ranges in the Southern and Northern hemispheres.[ citation needed ]
The density of cicadas over one 17-year cicada emergence period was found in one study to have dropped by one half due to infections from the fungus, while the number of infected cicadas producing resting spores increased by 9-fold. [12] This suggests the fungus can be utilized as a control agent in decreasing the significant damage cicadas impose on young trees on which they lay their eggs. [11] Studies of M. cicadina and its hosts can also provide insights into biological clocks and environmental signaling due to their long, synchronous life cycles.[ citation needed ]
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.
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.
Cicadidae, the true cicadas, is one of two families of cicadas, containing almost all living cicada species with more than 3,200 species worldwide.
The forest tent caterpillar moth is a moth found throughout North America, especially in the eastern regions. Unlike related tent caterpillar species, the larvae of forest tent caterpillars do not make tents, but rather, weave a silky sheet where they lie together during molting. They also lay down strands of silk as they move over branches and travel as groups along these pheromone-containing silk trails. The caterpillars are social, traveling together to feed and massing as a group at rest. Group behavior diminishes as the caterpillars increase in size, so that by the fifth instar (molt) the caterpillars are feeding and resting independently.
An entomopathogenic fungus is a fungus that can kill or seriously disable insects. They do not need to enter an insect's body through oral ingestion or intake; rather, they directly penetrate though the exoskeleton.
The Entomophthorales are an order of fungi that were previously classified in the class Zygomycetes. A new subdivision, Entomophthoromycotina, in 2007, was circumscribed for them.
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.
Entomophthora is a fungal genus in the family Entomophthoraceae. Species in this genus are parasitic on flies and other two-winged insects. The genus was circumscribed by German physician Johann Baptist Georg Wolfgang Fresenius (1808–1866) in 1856.
Entomophthora muscae is a species of pathogenic fungus in the order Entomophthorales which causes a fatal disease in flies. It can cause epizootic outbreaks of disease in houseflies and has been investigated as a potential biological control agent.
Aleeta curvicosta is a species of cicada, one of Australia's most familiar insects. Native to the continent's eastern coastline, it was described in 1834 by Ernst Friedrich Germar. The floury baker is the only described species in the genus Aleeta.
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.
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.
Magicicada tredecassini is a species of periodical cicada endemic to the United States. It has a 13-year lifecycle but is otherwise indistinguishable from the 17-year periodical cicada Magicicada cassini. 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.
Entomophaga grylli is a fungal pathogen which infects and kills grasshoppers. It is the causal agent of one of the most widespread diseases affecting grasshoppers. This is sometimes known as summit disease because infected insects climb to the upper part of a plant and grip the tip of the stem as they die; this ensures widespread dispersal of the fungal spores. The fungus is a species complex with several different pathotypes, each one of which seems to be host-specific to different subfamilies of grasshoppers. The pathogen is being investigated for its possible use in biological pest control of grasshoppers.
Massospora is a genus of fungi in the Entomophthoraceae family, within the order Entomophthorales of the Zygomycota. This has been supported by molecular phylogenetic analysis.
Strongwellsea is a genus of fungi within the order Entomophthorales of the Zygomycota. They are known to infect insects. Infected adult dipteran hosts develop a large hole in their abdomens, through which conidia (spores) are then actively discharged while the hosts are still alive.
Furia is a genus of fungi within the family of Entomophthoraceae. This has been supported by molecular phylogenetic analysis.
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: CS1 maint: multiple names: authors list (link)In the spring of 1851, during the imago appearance of the seventeen-year locust, among myriads of the insect, several friends and myself found between 12 and 20 specimens, which, though living, had the posterior third of the abdominal contents converted into a dry, powdery, ochreous-yellow, compact mass of sporuloid bodies. The caudal appendages and posterior two or three abdominal rings covering the mass, were loose and easily detached, leaving the fungoid matter in the form of a cone, affixed by its base to the unaffected part of the abdomen of the insect
Figs. 27, 28. Fungus mycelium, from the vagina of Cicada septendecim.
Fig. 29. Spores from the same situation as Figs. 27, 28.
The Cicada Fungus.—A number of specimens, mostly males, were found which had been attacked by the fungus, Massospora cicadina. This fungus was first noticed, we believe, by the late Dr. Joseph Leidy, who in 1851 found from 12 to 20 specimens of C. septendecim "which though living had the posterior third of the abdominal contents converted into a dry powdery, ochreous yellow, compact mass of sporuloid bodies." Dr. Leidy also described and figured the fungus itself. This fungus was also described by Prof. Peck in 1870, who gave it the name it now bears.
In the specimens which I found the entire abdominal cavity was tilled with a mass of spores, and the insects were still alive and able to "sing," although they were rather inactive. I did not find any portion of the fungus itself.
Spore mass occupying the abdominal cavity, whitish or pale cream-color, at length exposed by the falling away of the terminal rings of the abdomen; spores subglobose or broadly elliptical, granular within, sometimes containing one to three unequal nucleoli or oil globules, .00065′ — .00085′ in diameter.