Interesting. I wonder how the fungus adapted to target cicadas which famously spawn only in prime years such as 17 or 19 to avoid overlap with their predators.
Choose the non-teleolgical version: what changes did the fungus or cicada mutate that allowed this integration of lifecycles?
Good point. I guess you'd have to throw out the assumption they're not vulnerable during that time since they spend the bulk of their lifespan in the fungal domain: underground.
It's a parasite, not a predator. They can't live independently.