Natural Predators of Scissor Grinder Cicadas:
Who Eats Them?

Scissor grinder cicadas are among the most recognizable and sonorous insects found in many parts of North America, especially during the warm summer months. Their distinctive, continuous buzzing sound is not only a hallmark of the season but also a signal to numerous predators that a feast awaits. Despite their robust exoskeletons and loud calls, scissor grinder cicadas serve as a vital food source for many animals within their ecosystems. This article delves into the natural predators of scissor grinder cicadas, exploring who eats them and how these interactions shape local food webs.

Introduction to Scissor Grinder Cicadas

The scissor grinder cicada (Neotibicen pruinosus) is a species of annual cicada commonly found across the United States. It is named for its unique call, which sounds like the repetitive cutting of scissors—a sharp, rhythmic buzz that can be heard throughout summer days. These insects spend most of their life cycle underground as nymphs feeding on root sap before emerging to molt into adults, mate, and lay eggs.

Adult cicadas are relatively large, with greenish bodies and translucent wings with dark veining. While their size and noise help them evade some threats, they remain vulnerable to a variety of predators once above ground.

Why Predators Target Scissor Grinder Cicadas

Cicadas provide several advantages to predators:

• High Nutritional Value: Cicadas are rich in protein and other nutrients, making them a desirable prey.
• Abundance: Their synchronized emergence leads to large numbers appearing at once, providing ample food for many species.
• Relatively Slow Movement: Although capable of flight, cicadas are not particularly agile compared to other flying insects.

The combination of these factors makes scissor grinder cicadas an important seasonal resource for many animals.

Birds: The Most Common Cicada Predators

Birds are among the most prolific consumers of scissor grinder cicadas. Their keen eyesight allows them to spot these noisy insects amid leaves and branches easily.

Species That Feed on Cicadas

• American Robins (Turdus migratorius): Robins often pluck cicadas from tree branches or catch them mid-air.
• Blue Jays (Cyanocitta cristata): Known for their intelligence and opportunistic feeding behavior, blue jays actively hunt cicadas during peak emergence.
• Northern Cardinals (Cardinalis cardinalis): Cardinals use their strong beaks to crack open cicada exoskeletons and consume the soft inner parts.
• Crows and Ravens (Corvus spp.): These corvids take advantage of the abundance by snatching cicadas from perches or the ground.

Hunting Techniques

Birds typically catch cicadas by:

• Perching quietly near calling males and launching quick grabs.
• Snatching flying cicadas in mid-air.
• Foraging on foliage where cicadas rest between calls.

The loud calls of scissor grinders can actually attract birds from a distance.

Mammalian Predators

Several mammals include cicadas in their diets, primarily when other food sources are scarce or when cicada populations surge.

Common Mammalian Consumers

• Bats: Many bat species feed on flying insects at twilight or night. While cicadas mostly call during the day, some bats may opportunistically catch late-fluttering individuals.
• Raccoons (Procyon lotor): Raccoons forage extensively and will consume both live and fallen cicadas.
• Squirrels: Tree squirrels may eat cicadas found on bark or leaves.
• Skunks and Opossums: These nocturnal foragers will feed on dead or dying cicadas they find on the ground.

While mammals are not as specialized in hunting cicadas as birds, their opportunistic feeding habits ensure that they benefit from periodic cicada emergences.

Reptiles and Amphibians

Scissor grinder cicadas also fall prey to several reptile and amphibian species that inhabit overlapping environments.

Predatory Lizards and Snakes

• Anoles: These small lizards hunt insects actively during the day and may grab perched cicadas.
• Garter Snakes: While primarily eating smaller prey, garter snakes may seize incapacitated or grounded cicadas.

Amphibians

• Frogs and Toads: Though typically insectivorous on smaller prey, larger frogs might occasionally catch newly molted or slow-moving cicadas near water bodies.

Reptiles and amphibians contribute to controlling insect populations but likely play a smaller role relative to bird predation concerning adult scissor grinder cicadas.

Insect Predators: Nature’s Own Hunters

Several predatory insects also target scissor grinder cicadas at various life stages.

Cicada Killers (Sphecius speciosus)

One of the most infamous predators, the cicada killer wasp, hunts adult cicadas. Female wasps locate a cicada using visual cues, sting it to paralyze it temporarily, and drag it back to their burrow to serve as live food for developing larvae. This behavior is highly specialized; however, it primarily targets periodical rather than annual species but can still impact local scissor grinder populations where ranges overlap.

Praying Mantises (Mantodea)

Praying mantises are ambush predators that can catch adult or nymphal cicadas when they come within reach. Their camouflage allows them to blend into foliage perfectly before striking with lightning-fast precision.

Spiders

Large orb-weaver spiders sometimes trap adult scissor grinders in their webs. Though accidental from the spider’s perspective, such predation can remove individual adults from local populations.

Parasitism: A Hidden Threat

Beyond direct predation, scissor grinder cicadas face parasitism that weakens or kills them indirectly.

Parasitic Flies

Tachinid flies often lay eggs on adult cicadas. The larvae hatch inside the host’s body cavity, feeding internally until death ensues. This parasitism reduces adult survival rates significantly during mating seasons.

Fungal Pathogens

Entomopathogenic fungi like Massospora infect adult cicadas causing deformities or death before reproduction completes. While not predators in the classical sense, these fungi serve as natural population control agents.

Ecological Impact of Cicada Predation

The predation pressure on scissor grinder cicadas plays essential roles:

• Population Control: Prevents overpopulation and reduces damage caused by massive egg-laying in trees.
• Nutrient Cycling: Dead or consumed individuals recycle nutrients back into soil ecosystems.
• Food Web Support: Serve as critical high-energy food sources supporting birds, mammals, reptiles, amphibians, and insects during summer months.

This balancing act maintains ecosystem health in forests and urban green spaces alike.

Adaptations That Help Cicadas Evade Predators

Despite numerous predators targeting them, scissor grinder cicadas have evolved several defensive traits:

• Loud Calls: Can startle predators or signal alertness.
• Camouflage Coloration: Greenish-brown bodies blend with leaves and bark.
• Short Adult Lifespan: Limits exposure time above ground.
• Synchronized Emergence: Overwhelms predators through sheer numbers (“predator satiation”), ensuring enough individuals survive to reproduce.

These adaptations illustrate evolutionary arms races between prey and predator species.

Conclusion

Scissor grinder cicadas are integral components of many ecosystems during their active months each year. Their natural predators range widely across birds, mammals, reptiles, amphibians, insects, and even parasitic organisms—each contributing uniquely to regulating cicada populations. Understanding who eats these fascinating insects sheds light on complex ecological relationships vital for biodiversity conservation. Next time you hear the relentless buzzing chorus of a scissor grinder in summer heat, remember that this insect’s song is both an invitation to mate—and a dinner bell for myriad hungry creatures waiting nearby.