Natures wonders: fungus controls cicada sex activity (Introduction)

by David Turell , Thursday, February 22, 2018, 18:45 (2464 days ago) @ David Turell

Another fungus controls prey for its own purposes. We've seen ants controlled by fungus before. Convergence in evolution:

https://phys.org/news/2018-02-invasion-body-snatching-fungus.html

"UConn researchers recently documented in Nature Scientific Reports a gory and fascinating relationship between periodical cicadas and a fungus that infects them, hijacks their behavior, and causes a scene straight out of a zombie movie.

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"The story starts with the cicadas' emergence, when around 2 to 5 percent are infected with spores of a fungus called Massospora cicadina. Though the fungus infects both male and female cicadas, the researchers discovered that early in the emergence, the infection - at this point called a Stage I infection - causes curious behavioral changes in males where, in addition to their normal mating behaviors, they will exhibit wing flicking that is typically seen only in female cicadas.

"The infected male cicadas put on a ruse, much like the Sirens of Greek myths; they flick their wings like a female, and lure in healthy unsuspecting males, who get close enough to be exposed to the spores, leading to their doom. The diseased males will also attempt to copulate with the uninfected females, exposing them to even more spores.

"The infection results in the insect's abdomen becoming distended as it fills with powdery, white fungal spores eventually to the point of bursting open or falling off altogether. When the abdomen falls off, the genitalia are lost with it - but that doesn't stop the cicadas from their eager quest to copulate.

"Cicadas infected by the spores passed around by the initially infected cicadas exhibit what is called a Stage II infection, following the same infection cycle as that seen in Stage I infections, in some cases acting normally despite the lack of genitalia and large portions of their abdomens, and spewing spores wherever they go.

"The fungus's job is complete, the spores are spread and ready to infect future generations.

"Cooley says the research into similar infections by parasites or fungi has been observed in other species, for instance in beetles, fruit flies, and even mammals, and has led to a growing body of literature over the past 10 years or so.

"Of the cicada infections, Cooley says, "This phenomenon is the ultimate evolutionary arms race, where the host loses because they are rendered sterile or evolutionarily irrelevant by the fungus in order to spread the spores."

"He anticipates that this area of research will continue to heat up in coming years, as more details of these arms races are uncovered."

Comment: It is amazing how fungi do this. I suspect this developed in one type of fungus and was spread by horizontal transfer of genes.