Grasshopper Care & Lifespan Guide | Japanese Grasshoppers and Brown Grasshoppers: Housing & Diet

Grasshopper Keeping Basics: Start by Learning the Species

The two most common grasshoppers found in Japan are the Japanese grasshopper (Locusta migratoria) and the brown grasshopper (Acrida cinerea). Both are active as adults from summer through autumn (July–November) and are classic catches for children's insect collecting adventures.

Phase polymorphism (Japanese grasshopper): When population density increases, Japanese grasshoppers transition from solitary phase to gregarious phase, with dramatic changes in body color, wing shape, and behavior (increased flight capacity and darker pigmentation). In captivity, keeping 1–2 individuals is standard practice, and triggering the gregarious phase is avoided.

Grasshopper Keeping Quick Reference

Lifespan, diet, egg-laying, and overwintering are essentially shared between the two species.

Collection Tips and Transport Home

Collection season: July through late October, with peak activity August–September when adults are most abundant.

Collection locations:

• Japanese grasshopper: River floodplains, farmland edges, vacant grassland
• Brown grasshopper: Areas with tall grass-family plants (pampas grass, Miscanthus transmorrisonensis), embankments, and meadows

Collection equipment:

• Insect net (large mesh net works best)
• Insect housing container (use a breathable container after collection)
• Cooler bag (to prevent overheating during transport)

Transport precautions: Grasshoppers are heat-sensitive, so direct sunlight and leaving them in hot vehicles is prohibited. After collection, quickly move them to a cool location and housing container. Since grasshoppers are highly active jumpers, prioritize ventilation over airtight sealing when choosing a container.

Housing Container Setup

Since grasshoppers excel at flight and jumping, a vertically tall container is ideal.

Recommended containers: Tall insect-rearing plastic containers (30 cm+ height) or mesh enclosures 100+ cm tall (fabric, excellent ventilation). Brown grasshopper females are especially large and can injure themselves quickly in cramped spaces.

Substrate:

• Layer 3–5 cm of soil or coconut husk to create a natural environment
• No substrate is also acceptable (prioritizing cleanliness), but add wooden branches or artificial plants as perches

Perches and footholds:

• Place several thin wooden branches upright
• Add potted grass-family plants (foxtail millet, Miscanthus) to serve as both food and perch

Temperature and humidity:

• Temperature: 25–32°C (sensitive to cold)
• Humidity: 50–70% (slightly dry is fine)
• Place in a bright location, avoiding direct sunlight

Feeding

Grasshoppers are herbivorous and feed primarily on grass-family plants. Providing fresh food daily is essential for maintaining health.

Primary food sources:

• Foxtail millet (Setaria viridis): The most popular and readily eaten option
• Miscanthus, pampas grass, various wild grasses: Wild vegetation
• Barley and rice shoots: Home-grown options work well
• Cabbage and lettuce leaves: Supplementary use (watch for excess moisture)

Feeding tips:

1. Collect wild grasses from pesticide-free areas
2. Rinse away excess soil
3. Replace with fresh grass every other day (old grass is rejected)
4. Place directly on the container floor, or insert into a small vase with water to extend freshness

Hydration: Grasshoppers obtain sufficient water from the grass itself, so a separate water dish is unnecessary. During hot weather, a light misting of the leaves is sufficient.

Molting and Growth Management

Grasshoppers undergo 5–6 molts before reaching adulthood (nymph stages: 5–7 instars). Immediately after molting, their bodies are soft and may be eaten by other grasshoppers in the container, so caution is needed.

Pre-molt signs:

• Reduced appetite
• Becomes quiet and clings to perches
• Body color darkens slightly

During molting:

• Never touch the grasshopper while molting
• Ensure perches (branches, stems) are sturdy
• Leave undisturbed for 6–12 hours after molting while the body hardens

Post-molt recovery: Appetite returns the day after molting. Provide abundant fresh grass.

Egg-Laying and Egg Management

Adult grasshoppers mate and lay eggs. Since eggs are laid underground, provide soil at least 10 cm deep (mixed red loam and leaf mold) in the housing container.

Clutch size: A single egg-laying event produces 20–100 eggs in an egg pod. Brown grasshoppers characteristically produce foamy egg pods containing many air pockets.

Overwintering: Japanese grasshoppers do not survive winter as adults. As autumn ends, adults die, and eggs in the soil overwinter, hatching the following spring.

Egg management:

• Keep the soil with eggs in a container and place in a shaded outdoor location for winter
• Wait for nymphs to hatch in spring (April–May)
• Mist regularly to prevent the soil from drying out completely

Grasshopper Lifespan: How Long Do They Live? The Complete Life Cycle from Egg to Adult

The adult lifespan of both Japanese grasshoppers and brown grasshoppers is approximately 2–3 months. Individuals that become adults in August typically reach the end of their natural lifespan by October–November. When considering the entire life cycle including the egg stage, both species complete approximately one generation per year.

Japanese grasshoppers are known to have two generations per year (bivoltine) in warmer regions. Eggs laid in early summer hatch within a single summer season, producing a second generation of adults in autumn. In contrast, eggs laid in autumn overwinter in soil and hatch the following spring. For managing autumn-laid eggs in captivity, follow the "Egg-Laying and Egg Management" section described above.

How Long Can You Keep Them Alive in Captivity?

Wild adults die as temperatures drop, but in captivity with fresh food and consistent temperature (25–32°C), they consume resources more slowly and may be observed longer than in nature. Three key strategies extend their lifespan:

1. Never run out of fresh grass-family plants: Without fresh grass, appetite drops and they deteriorate rapidly
2. Maintain temperature: Cold is lethal, so after autumn, keep the container in a sunny indoor location to maintain warmth
3. Avoid overcrowding: Reduces stress and cannibalism risk

Why Does Cannibalism Occur? How to Prevent It

Although herbivorous, grasshoppers sometimes eat freshly molted, soft individuals or weakened ones—a behavior called cannibalism. This usually stems from overcrowding in small containers and food shortage. Prevention strategies include:

• Limit container occupancy to 2–3 individuals
• Always provide abundant fresh grass
• Isolate individuals showing pre-molt signs (reduced appetite, clinging quietly to perches) in separate containers

Other Husbandry Considerations

• Clean containers weekly to remove feces and old plant material
• Avoid collecting from areas with invasive species or pesticide contamination
• If releasing captive grasshoppers outdoors, limit it to the original collection site

Summary: The Joy of Grasshopper Keeping

Grasshoppers offer the unique opportunity to observe a complete year-long cycle from collection through breeding and hatching—making them excellent nature study subjects, especially for children. The experience of witnessing the life cycle—from outdoor collection to captive rearing to egg-laying to hatching—is invaluable.

While caring for them requires effort (gathering fresh grass, preparing soil for egg-laying), the care investment builds genuine attachment. They excel as summer vacation research projects, and keeping detailed observation records deepens learning and understanding of their biology.