A fungus called Massospora cicadina is infecting cicadas in the Northeast. West Virginia University researchers studying the fungus have found amphetamines and some properties only previously found in psychedelic mushrooms. Matt Kasson, a forest pathologist and professor at West Virginia University, spoke with Kiley Koscinski about his team’s research on the fungus for a recent episode of The Confluence from 90.5 WESA
KK: The headlines are sensational: zombie bugs are among us. But this fungus you’re studying, Massospora cicadina, is sort of inhibiting these bugs from controlling their own bodies. Is that right?
MK: That’s correct.
KK: So how is this fungus affecting cicadas?
MK: Well, the fungus has a long co-evolved relationship with the cicadas. It’s been infecting them for as long as cicadas have been around, and it kind of modifies behaviors in two ways. The first is that it seems to enhance the typical behaviors of cicadas. We see infected cicadas flying around a lot, engaging in mating behaviors. A lot of that is typical of healthy individuals.
Then there’s this kind of hypersexualization, where infected individuals, males for example, in addition to attempting to mate with females, will also pretend to be females to engage with males, to further spread the fungus. This is all behavioral modification on the part of the fungus, to ensure that it’s spread to as many individuals as possible.
KK: So where does this fungus live, and how does it attach itself to the cicadas?
MK: The fungus, for a good part of its life cycle, hangs out underground in the form of these really thick-walled spores. They start to interact with the cicadas when they come up in the 17th year, as they get ready to emerge and molt into adults. They do produce these kind of vertical emergence chambers subsurface, right below bricks and right below leaves. It’s there where they first encountered the spores. We believe that the spores are actually cuing into the hormones of the cicadas. That’s how they know to germinate. That’s how they know that they’ve found the right host.
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KK: Spreading on one host, it sort of replaces that part of the bug, and that part of the bug becomes like a sculpture of the bug. But it’s the fungus?
MK: That’s right. It looks a lot like the abdomen, it’s shaped like the abdomen, but it’s all fungal tissue. You know, the cicadas that are infected, it’s like they don’t even notice that the whole backside of their body has been replaced by fungal tissue. That’s why they continue to engage in these activities. We hypothesize that these compounds we found in these fungi could explain why they continue to do this, despite the fact that a third to half their body has completely fallen off and has been replaced by this fungus.
KK: WVU researchers, including yourself, have been learning about the chemical makeup of Massospora. How does it work?
MK: What we found is that there were about 1,000 to 1,500 unique compounds that were present only in the fungal plugs, and of those compounds, a few of them stood out because they are known alkaloids. Alkaloids are these interesting metabolites that have known impacts on vertebrates, including psilocybin and cathinone, which were two of the ones that we highlighted in our study. I want to emphasize the fact that although we focus on these two psychedelic compounds, there were over a thousand compounds.
KK: I just want to clarify that those two compounds are the chemicals in hallucinogenic mushrooms, correct?
MK: Well, one of them, psilocybin, is the active component in hallucinogenic mushrooms. The other compound, cathinone, is actually an amphetamine that’s found in a native cat plant which is found in the Horn of Africa, and utilized in the Arabian Peninsula.
KK: We know how those affect humans. Do we know anything about how they’re affecting the cicadas?
MK: This is kind of the complicated part of the project. Both of these compounds are DEA regulated. Fortunately for us, there were a lot of studies done on the impacts of these compounds on invertebrates, including insects, back in the 60s and 70s.
We know for example that when you give ants amphetamines, they get more aggressive. We know that if you give spiders psilocybin or LSD, they produce really unusual webs. They call them drug webs. So there are a number of studies that we can lean on, and start to understand how these compounds may impact invertebrates.
KK: So if the fungus takes over part of their body, how are these cicadas still living? How are they still moving around and flying?
MK: That’s really the question we asked when we first started this study. We would find individuals where a third to half of their body was missing, and yet they were moving around as if nothing had happened. It was that kind of prolonged wakefulness that really drove our research question. We know, for example, that during war combat, soldiers were given amphetamines. And we know that gave them increased stamina, and we’re seeing that probably to be true in the cicada system,
KK: Are there any implications for humans that might come in contact with this fungus? Is there something humans should be doing to prevent it from spreading?
MK: No, not necessarily. The question we get a lot is if I eat one of these cicadas, will I trip or will it cause euphoria? The dose is pretty low; it would take a lot of cicadas to really impact a human. But with regard to the impact on humans, it is really more of a pharmaceutical impact. If we find novel bio synthetic routes for these compounds, it might make it easier to synthesize some of these compounds in the lab. We might find novel intermediate compounds that could have some utility in medicine, or in the pharmaceutical industry.
Finding that these compounds are present really raises the question, what else is out there? How could we utilize them for human medicine, or how could we utilize them as a pharmaceutical for different illnesses? We’re still in the discovery phase, but as we uncover more and more compounds, potentially, and these other behavior modifying insect pathogens, it might be the next front bioprospecting.