Their perfect periodicity and overwhelming abundance suggests that periodical cicada populations likely satiate their predators above ground, limiting the need for predator avoidance behavior. Periodical cicadas can reproduce at the tremendous densities required to sustain their populations. Possibly the most important ecosystem function of periodical cicada emergence may be providing increased energy and nutrients to predators. The biomass represented by an emergence can be tremendous, and it benefits predator populations considerably. The only synchronized natural enemy of the periodical cicada is the host-specific fungus Massospora cicadina.
Infection takes place below ground, after infected nymphs hatch.
Infected cicadas can invade new habitat, taking the fungus, which is extremely infective to other adults, with them. Fungal infection reduces the reproductive success of both males and females. Random natural events, such as violent summer storms, also contribute to periodical cicada mortality. Preliminary Monthly Climatological Data for Selected Ohio Locations, January 1999 Weather Station Location Monthly Prec. Normal Monthly Prec.