A deadly fungus horrifically kills flying insects by rotting their innards, causing their limbs and genitals to drop off while they are driven into a hypersexual frenzy.
The fungus infects the young of the insects, cicadas, which live underground, lying dormant for up to 16 years until the insects emerge as adults above the surface.
The fungus then slowly pushes out of the insects’ rears, killing them slowly — but not before making them shed spores and try to mate with male and female cicadas alike.
US researchers studying the bizarre infection have found that the fungus contains chemicals similar to those found in hallucinogenic mushrooms.
Studying fungi like these could help discover new medical drugs, researchers said.
Scroll down for video
In a fate that would chill even George A Romero, fungus-infected cicadas face a ‘flight of the living dead’ as they turn into rotting, hypersexual, infectious zombies
HOW DO CICADAS TURN INTO ‘ZOMBIES’?
Young cicada spend around 13–17 years underground.
The flying adults live for only up to six weeks after emerging.
The young encounter the Massospora cicadina fungus underground, where the infection can be dormant for years.
Researchers found that visible signs of the infection can appear within ten days of emerging above ground.
The fungus grows in the soft part of the insect’s abdomen, pushing slowly out of their rears to reveal a spore-releasing mass.
The insects slowly rot and their limbs and genitals often drop off — but still they carry on moving, spreading the infection in their wake.
Infected adults often engage in frenzied activities and hypersexual behaviour — mating with female and male cicadas alike.
This turns the afflicted insects into infectious ‘zombie’ agents.
Insect-loving researchers at the West Virginia University in Morgantown were prompted to study the ghastly fungus, known as Massospora cicadina, after a swarm of billions of the cicadas emerged in the northeastern US back in 2016.
Although they were unable to infect cicadas with the fungus in their lab, they were able to study enough infected insects in the wild to discover that Massospora contains the same kinds of chemicals found in hallucinogenic mushrooms.
Young cicada spend around 13–17 years living underground feeding on tree roots before emerging at the surface as flying adults that only live for up to six weeks.
This life cycle is thought to have evolved to protect them from shorter-lived predators — making the cicada a less reliable food source — but it is in their underground refuge that the young insects can encounter the deadly fungus.
Researchers found that visible signs of the infection can appear within ten days of emerging above ground, as the zombie-like insects’ abdomens begin to rot, sloughing off to reveal the mass of fungus erupting out of their rears.
‘They are only zombies in the sense that the fungus is in control of their bodies,’ said study author and forest pathologist Matt Kasson.
While the infection can render the cicadas infertile, causes their legs to drop off and gradually rots them from the inside out, it does not kill the insects straight away and still lets them walk and fly around like normal, dropping deadly spores in their wake.
It is this behaviour that prompted West Virginia University PhD candidate Angie Macias to dub the infected cicadas the ‘flying salt shakers of death’.
‘Infected adults maintain or accelerate normal host activity during sporulation, enabling rapid and widespread dispersal prior to host death,’ Professor Kasson explained.
‘They also engage in hypersexual behaviours,’ he added.
In this way, the patient fungus turns the ‘zombie’ insects into its own infection-spreading agents.
The fungus can infect young cicadas that live underground, lying dormant for up to years until the insects emerge as adults above the surface
With this study complete, the researchers are now planning to sequence the genome of Massospora and compare the different gene expressions within healthy and infected cicadas to learn more about how the infection takes hold.
To this end, the team has recently been collecting cicadas from this year’s emergence in both Pennsylvania and West Virginia.
The research may lead to practical applications.
‘We anticipate these discoveries will foster a renewed interest in early diverging fungi and their pharmacologically important secondary metabolites, which may serve as the next frontier for novel drug discovery,’ said Professor Kasson.
The fungus then slowly pushes out of the insects’ rears, killing them slowly — but not before making them shed spores and try to mate with male and female cicadas alike
‘I love them,’ Professor Kasson said of the insects he studies.
‘They still scare me when they fall down my shirt or walk up my neck,’ he added.
‘But I can appreciate something that spends almost two decades underground for six weeks of bliss, with or without the fungus.’
The full findings of the study were published in the journal Fungal Ecology.
‘I love them,’ West Virginia University professor Mark Kasson said of the insects he studies. However, he added, ‘they still scare me when they fall down my shirt or walk up my neck.’