A new paper, A specialized fungal parasite (Massospora cicadina) hijacks the sexual signals of periodical cicadas (Hemiptera: Cicadidae: Magicicada), has been published by John R. Cooley, David C. Marshall & Kathy B. R. Hill, in Scientific Reports 8, Article number: 1432 (2018).
Read the paper online.
In a nutshell: the fungus infects males and causes them to exactly mimic the mating behavior of female cicadas, thus infected males end up spreading the fungus to uninfected males.
Male periodical cicadas (Magicicada spp.) infected with conidiospore-producing (“Stage I”) infections of the entomopathogenic fungus Massospora cicadina exhibit precisely timed wing-flick signaling behavior normally seen only in sexually receptive female cicadas. Male wing-flicks attract copulation attempts from conspecific males in the chorus; close contact apparently spreads the infective conidiospores. In contrast, males with “Stage II” infections that produce resting spores that wait for the next cicada generation do not produce female-specific signals. We propose that these complex fungus-induced behavioral changes, which resemble apparently independently derived changes in other cicada-Massospora systems, represent a fungus “extended phenotype” that hijacks cicadas, turning them into vehicles for fungus transmission at the expense of the cicadas’ own interests.
And now, because I need an image for the post: a meme:
Cicadas, when infected, are called “salt shakers of doom”. Add that to the meme “Salt Bae”, and the image makes sense.
A “Salt-Shaker of Death”. (Deadly for the cicada, not humans.)
Many types of fungi will eat cicadas, but one type — the Massospora — specifically infests and destroys cicada genitalia. Specifically, Massospora cicadina attacks Magicicada cicadas, and Massospora levispora attacks Okanagana rimosa. According to the website MycoBank Database, there’s at least 19 species of Massospora. By the names of some, you can guess which cicada it infects; Massospora diceroproctae likely infects Diceroprocta cicadas.
It’s not certain, but there are sure to be many more species of Massospora fungi — if not one for each species, perhaps approximately one for each genus. Considering that Massospora infects cicadas all around the world, it’s fair to assume that Massospora has been infecting cicadas for many millions of years.
At West Virginia University, Matt Kasson & his team are studying Massospora, and are looking for samples of cicadas with these infections. Matt regularly Tweets photos and finding such as this one of spores from a Platypedia cicada:
If you have some samples of such cicadas and are willing to part with them, let Matt know.
What eats cicadas? A better question is: what doesn’t eat cicadas?
Pretty much every creature with a mouth will eat a cicada, given the chance. Even organisms without mouths like fungi will consume cicadas.
People, pets, rodents, marsupials, reptiles, birds, fish, insects, arachnids — virtually any creature will eat them.
Some insects are known for specifically preying on cicadas, for example, Cicada Killer Wasps are well known for capturing cicadas for their larvae to eat them.
What eats them when they’re underground? When they’re underground they’re often eaten by moles and other furry insectivores, but enough of them escape the moles for the species to survive.
Read are cicadas safe to eat if you’re planning a cicada buffet.
The fungus Massospora cicadina preys on Magicicadas cicadas. This is particularly interesting because the fungus is able to prey upon them in spite of their long 17 year life cycle (apparently fungi are not phased by prime numbers).
When the fungus destroys the abdomen of male cicadas, they will behave like female cicadas and flick their wings in response to the songs of male cicadas, and attempt to mate with other males.
A photo by Roy Troutman from Brood XIV (2008):
Two photos by Dan Mozgai from Brood II (2013):
Magicicada fungus (massospora cicadina)
magicicada fungus (massospora cicadina) from Roy Troutman.
New from 2017: the Massospora cicadina viewed under a microscope.