Grasshoppers are among the most recognisable insects on earth, famed for their powerful hind legs and the chirping songs males produce on warm summer days. Belonging to the order Orthoptera and the suborder Caelifera, there are roughly 11,000 described species worldwide. Almost all of them are herbivores, and their feeding habits can have enormous ecological and economic consequences.
General Diet Overview
The vast majority of grasshoppers feed on living plant material. Their chewing mouthparts are well adapted for cutting and grinding leaves, stems, seeds, and flowers. While some species are generalist feeders that consume a wide range of plants, others are specialists restricted to one or a handful of host plant families.
| Diet Category | Description | Example Species |
|---|---|---|
| Graminivorous | Feeds primarily on grasses (Poaceae) | Field grasshopper (Chorthippus brunneus) |
| Forbivorous | Feeds mainly on broad-leaved herbaceous plants | Stripe-winged grasshopper (Stenobothrus lineatus) |
| Mixed feeder | Consumes both grasses and forbs | Meadow grasshopper (Pseudochorthippus parallelus) |
| Polyphagous | Eats a very wide range of plant species | Desert locust (Schistocerca gregaria) |
Grasses: The Primary Food Source
For many grasshopper species, grasses form the bulk of the diet. Graminivorous grasshoppers consume the leaf blades of species such as ryegrass, timothy, fescue, and wild oat. The silica content in grass leaves wears down their mandibles over time, but the mandibles continue to grow throughout their lives to compensate for this abrasion.
In agricultural settings, grasshoppers readily feed on cereal crops including wheat, barley, maize, rice, sorghum, and millet. During outbreak years, swarms of locusts — which are grasshoppers that have entered a gregarious phase — can devastate millions of hectares of cropland.
Broad-Leaved Plants and Garden Crops
Forbivorous and mixed-feeding grasshoppers also target broad-leaved plants. In gardens, they may consume lettuce, beans, carrots, onion foliage, and brassica leaves. Wild plants eaten include clover, dandelion, plantain, and various composites (Asteraceae).
Plants Grasshoppers Commonly Eat
- Grasses: Ryegrass, fescue, timothy, wheat, barley, maize
- Legumes: Clover, alfalfa, beans, peas
- Vegetables: Lettuce, carrots, brassicas, onion foliage
- Wild forbs: Dandelion, plantain, yarrow, ragwort
- Flowers: Sunflowers, marigolds, zinnias (petals and leaves)
How Grasshoppers Feed
Grasshoppers possess strong mandibles that move from side to side rather than up and down. They grip a leaf edge, cut crescent-shaped notches, and systematically work their way along. A single adult grasshopper can eat roughly half its own body weight in plant material per day. When populations are dense, the cumulative damage is severe.
Nymph vs Adult Feeding
Grasshopper nymphs (the immature stages) feed on the same types of food as adults, though they tend to select younger, softer plant tissues because their mandibles are not yet fully hardened. As they moult through five or six instars, they gradually shift to tougher foliage.
Did you know? A single desert locust can eat its own body weight — about 2 grams — of food every day. A small swarm of one billion locusts can consume as much food in a day as 35,000 people.
Do Grasshoppers Ever Eat Other Insects?
While grasshoppers are overwhelmingly herbivorous, occasional omnivory has been documented. Under conditions of crowding or food scarcity, some species have been observed scavenging on dead insects or even cannibalising weaker individuals. This behaviour is particularly noted in locust swarms, where competition for resources is extreme. However, animal matter forms an insignificant portion of the normal diet.
The Agricultural Impact
Grasshoppers are among the most economically important agricultural pests worldwide. In sub-Saharan Africa and the Sahel, desert locust outbreaks threaten food security for millions of people. In North America, rangeland grasshoppers cause hundreds of millions of dollars of damage to crops and pastureland annually. Even in the UK, where species are less destructive, grasshoppers occasionally damage garden crops during warm, dry summers.
Factors That Trigger Outbreaks
- Warm, dry weather increases egg survival and accelerates nymph development.
- Reduced natural enemies — parasitic flies, birds, and fungal pathogens — allow populations to grow unchecked.
- Overgrazing creates the bare, warm soil grasshoppers prefer for egg-laying.
- Drought-stressed plants concentrate sugars, making them more attractive to feeding grasshoppers.
- Phase change (in locusts) — crowded nymphs develop into gregarious, swarming adults that migrate en masse.
Natural Predators That Control Grasshopper Populations
Many animals depend on grasshoppers as a food source, helping to regulate their populations naturally. Birds such as starlings, kestrels, and meadow pipits consume large numbers. Parasitoid flies (Sarcophagidae), blister beetle larvae that feed on grasshopper egg pods, and entomopathogenic fungi (Metarhizium acridum) also play critical roles in population control.
Key Takeaway
Grasshoppers are herbivorous insects that feed primarily on grasses and broad-leaved plants. Their diet includes many important agricultural crops, and during outbreak years, they can cause catastrophic damage. Understanding their feeding preferences is essential for pest management and for appreciating their role in grassland ecosystems.