What Eats Grasshoppers? Natural Predators for Garden Pest Control

Grasshoppers (family Acrididae) are voracious herbivores capable of consuming up to 50% of their body weight in plant matter daily. When populations exceed the economic threshold of 8 to 14 nymphs per square yard, they can strip a home garden of its foliage in a matter of days. While chemical insecticides like carbaryl and bifenthrin offer immediate knockdown, they also devastate beneficial pollinators and disrupt local food webs. Understanding what eats grasshoppers naturally allows homeowners to leverage biological control agents—ranging from avian hunters to microscopic pathogens—to maintain long-term ecological balance.

Avian Allies: Birds That Hunt Grasshoppers

Birds are the most visible and effective vertebrate predators of grasshoppers. Insectivorous and omnivorous species actively hunt both nymphs and adults, particularly during the breeding season when protein demands are high.

Top Grasshopper-Hunting Bird Species

• Barn Swallows (Hirundo rustica): Aerial insectivores that catch adult grasshoppers mid-flight. A single breeding pair can consume thousands of insects per week.
• Eastern Bluebirds (Sialia sialis): Ground-foraging hunters that spot nymphs from perches and strike rapidly. They prefer open lawns bordered by shrubbery.
• Northern Mockingbirds (Mimus polyglottos): Aggressive territorial defenders that will impale large grasshoppers on thorns or barbed wire for later consumption.
• American Robins (Turdus migratorius): While known for earthworms, robins readily consume early-instar grasshopper nymphs in damp soil and turf.

Poultry and Reptilian Ground Hunters

For larger properties or rural homesteads, integrating domestic poultry and encouraging native reptiles provides relentless ground-level pest control.

Guinea Fowl: The Ultimate Biocontrol

Guinea fowl (Numida meleagris) are widely considered the most effective poultry species for grasshopper management. Unlike chickens, which scratch and damage shallow root systems, guinea fowl peck and hunt without destroying garden beds. During peak summer months, adult guinea fowl derive up to 40% of their daily caloric intake from foraging for grasshoppers, ticks, and beetles. A flock of 10 to 15 birds can effectively patrol a 1-acre homestead, significantly reducing nymph survival rates before they reach reproductive maturity.

Native Reptiles and Amphibians

The Eastern Fence Lizard (Sceloporus undulatus) and various native toad species (such as the American Toad, Anaxyrus americanus) are ambush predators that thrive in garden margins. Toads can consume their body weight in insects nightly. Retaining leaf litter, installing low-growing groundcovers like creeping thyme, and providing shallow water dishes with sloped edges will encourage amphibian residency.

Invertebrate Predators and Parasitoids

Beneath the canopy and within the soil, a complex web of invertebrates preys on grasshoppers. According to the University of Minnesota Extension, preserving these natural enemies is critical for integrated pest management (IPM).

"Broad-spectrum insecticides often trigger secondary pest outbreaks by eliminating the very parasitoid wasps and predatory beetles that keep grasshopper and aphid populations in check." — IPM Best Practices Guide

Key Invertebrate Agents

• Robber Flies (Family Asilidae): Large, aggressive flies that intercept adult grasshoppers in mid-air, injecting neurotoxic saliva that paralyzes the prey instantly.
• Ground Beetles (Family Carabidae): Nocturnal hunters that consume grasshopper eggs deposited in the soil during late summer and early autumn.
• Blister Beetles (Family Meloidae): While their larvae parasitize grasshopper egg pods, adults can damage crops and contain cantharidin, a toxin harmful to livestock. Encourage them in ornamental zones, but monitor near horse pastures.

Microscopic Predators: Fungal and Protozoan Pathogens

When physical predators are insufficient, biological pesticides utilizing naturally occurring pathogens offer highly targeted control. These agents specifically disrupt grasshopper biology without harming mammals, birds, or beneficial insects.

Nosema locustae (Protozoan Parasite)

Commercially available under trade names like Nolo Bait or Semaspore, Nosema locustae is a microsporidian protozoan that infects the grasshopper's fat body and digestive tract. Infected nymphs become lethargic, stop feeding, and eventually die. Furthermore, cannibalism among grasshoppers spreads the spores through the population.

• Application Rate: 1 pound per acre (broadcast using a drop spreader).
• Timing: Must be applied in early spring when nymphs are in their 2nd or 3rd instar (approx. 0.5 inches long). Adults are highly resistant.
• Cost: Typically $35 to $45 per pound.

Entomophaga grylli (Fungal Pathogen)

This naturally occurring fungus causes "summit disease," where infected grasshoppers climb to the top of a plant, clamp their mandibles onto a stem, and die, allowing the fungus to rain spores down on the population below. While you cannot purchase E. grylli commercially, avoiding broad-spectrum fungicides in your yard allows this native fungus to thrive during humid summer periods.

Grasshopper Predator Selection Matrix

Choosing the right biological control depends on your property size, the grasshopper life stage, and your budget. Use the matrix below to design your IPM strategy.

Step-by-Step Habitat Engineering for Predator Retention

Attracting predators is only half the battle; retaining them requires specific botanical and structural modifications to your landscape.

1. Plant Umbelliferous Nectar Sources: Adult parasitoid wasps and robber flies require nectar for energy. Plant Achillea millefolium (Yarrow), Foeniculum vulgare (Fennel), and Daucus carota (Queen Anne’s Lace) along garden borders to provide continuous bloom from June to September.
2. Establish "Beetle Banks": Create raised soil berms (18 inches wide, 6 inches high) planted with native bunchgrasses like Little Bluestem. These banks provide overwintering habitat for ground beetles, ensuring they are present when grasshoppers lay their eggs in late summer.
3. Install Shallow Hydration Stations: Predators need water. Bury a terracotta saucer flush with the soil line and fill it with pebbles and water. This allows toads and lizards to drink without the risk of drowning associated with deep birdbaths.
4. Cease Preventative Soil Drenches: Avoid applying systemic neonicotinoids (like imidacloprid) to ornamental shrubs. These chemicals translocate into the pollen and nectar, killing the very robber flies and wasps that hunt adult grasshoppers.

By shifting from reactive chemical sprays to proactive habitat management, homeowners can build a resilient ecosystem. For further reading on regional grasshopper species and economic thresholds, consult the Colorado State University Extension or the USDA APHIS Grasshopper Control Program guidelines.

Frequently Asked Questions

Do spiders eat grasshoppers?
Yes. Large orb-weaver spiders (like the Yellow Garden Spider, Argiope aurantia) and wolf spiders will capture and consume grasshoppers. However, they are opportunistic and cannot be relied upon as a primary population control method.

What is the best time of day to encourage bird predation?
Birds are most active in foraging during the early morning (6:00 AM to 9:00 AM) and late afternoon. Ensure your bird feeders and birdbaths are stocked and clean before dawn to maximize their hunting window in your garden.