Cicadas, with their long underground lifecycles and brief, noisy adult emergences, represent a massive, concentrated food source for many organisms. Both annual and periodical species (emerging every 13 or 17 years) offer a high-protein, defenseless meal. This sudden glut of food causes many predators to temporarily shift their diets. The sheer number of insects, particularly during a periodical emergence, is a survival strategy known as predator satiation, ensuring enough survive to reproduce.
Avian Hunters
Birds are among the most visible and numerous predators to capitalize on a cicada emergence, viewing the insects as a dense nutritional resource. Many avian species, from generalists to insect specialists, adjust their foraging habits to consume the insects in high volumes. Species like American Crows, Blue Jays, European Starlings, and Common Grackles are frequently observed gorging themselves.
The temporary abundance of this food source can have measurable effects on bird populations, with some species experiencing increased nestling body mass and survival rates during emergence years. Ground-feeding birds, such as wild turkeys and chickens, also benefit by picking off newly emerged or fallen adults.
Ground-Level Mammals and Reptiles
Predation is not limited to the above-ground adult stage; a variety of animals target the nymphs before and during their final ascent. Burrowing mammals, including moles and shrews, consume cicada nymphs while tunneling through the soil. Skunks also actively excavate the ground to find and consume the nymphs.
As the nymphs crawl out of the ground to molt into adults, they become vulnerable to opportunistic surface hunters. Raccoons and foxes forage for the insects, and domestic pets, such as dogs and cats, will eagerly consume them. Reptiles like copperhead snakes climb trees to feed on the insects, and turtles snack on any adults that fall into the water.
Insect and Arachnid Specialists
The most dramatic invertebrate predator is the Cicada Killer Wasp (Sphecius speciosus), a large, solitary wasp that has specialized its life cycle around its prey. The female wasp hunts for adult cicadas, often catching them in flight, and delivers a paralyzing sting. This venom immobilizes the cicada but keeps it alive, ensuring a fresh host for the wasp’s offspring.
The paralyzed cicada is dragged or flown back to an underground burrow the female has dug in loose soil. She deposits one to three cicadas into a cell, lays a single egg on one of them, and then seals the chamber. When the egg hatches, the larva consumes the paralyzed cicada, completing its development before overwintering in the burrow. Other invertebrates, like praying mantises and large spiders, also opportunistically prey on adult cicadas.
Fungal and Pathogenic Threats
Cicadas face threats from the microbial world, most notably the specialized fungus Massospora cicadina, which targets periodical cicadas. This fungus does not kill its host immediately but replaces the rear abdominal segments with a chalky mass of spores, effectively castrating the insect. The fungus contains psychoactive compounds, which are believed to chemically manipulate the cicada’s behavior to maximize spore dispersal.
Infected males are induced to exhibit a wing-flicking signal that normally only sexually receptive females perform, which attracts uninfected males attempting to mate. This highly unusual behavior, combined with the loss of the abdomen’s terminal segments, turns the infected cicada into a mobile dispenser, spreading spores through attempted copulation. The fungus hijacks the host, ensuring its own transmission before the cicada finally dies.