© User:ツキ / CC BY-SA 3.0Ritsema's Giant Stag Beetle
Ritsema's Giant Stag Beetle is native across Southeast Asia's islands and shows some of the widest regional variation of any stag beetle. Local forms from Java, Sumatra, Borneo, and Mindanao are traded under their island names, each with a subtly different body shape and jaw form. It's hardy and long-lived, with adults surviving two to three years, so keepers can enjoy watching one beetle for a long time. Males carry an imposing pair of mandibles while females have a rounder, more compact build, adding visual variety within a single species. That hardiness also makes it a good choice for first-time stag beetle keepers.
View Ritsema's Giant Stag Beetle encyclopedia →0% commission on your first sales!Register by September 30, 2026 and your first 2 sales are commission-free!
Breeder Wanted!
List on BreederDirect and sell directly to customers nationwide!
6 Transparency Standards You Can Trust
When listing Insects, Breeders disclose the following. We guarantee transparency on growth stage and breeding unit.
- Life Stage Clarity
- Generation Info
- Real Photos
- Breeding Unit
- Country of Origin
- Body Length (mm)
Browse all 296 breeds
Verified breeders wanted for Insects
Breeders are signing up now ahead of launch. Subscribe to be notified when new listings go live.
Getting alerts is free with a member account. When new listings match your saved search, we'll notify you by email and in-app.
Browse other categories
Verified breeders (preview)
Ritsema's Giant Stag Beetle key facts
- Care level
- Beginner-friendly
- Lifespan
- Adults 2-3 years
- Size
- Males 28.2-79.0mm, females 29.3-41.5mm
- Temperature
- 18℃
- Diet
- Beetle jelly; larvae on fungus bottles or fermented substrate
- Temperature & Humidity
- Room temperature works. Keep summers below 30C; activity slows under 18C. For winter breeding keep at least 20C.
- Breeding & Egg-laying
- Eggs are laid in decaying logs or fermented substrate; rear larvae on fungus bottles. Larvae take 6-24 months.
- Cohabitation
- House each sex singly; never keep males together. Cohabit only for pairing.
- Lifespan & Rearing Period
- Adults live 2-3 years. Larval period is 6-24 months depending on conditions.
- Health & Notes
- Avoid extreme dryness and stuffiness. Seven subspecies are traded by locality, so never mix subspecies or localities.
About Ritsema's Giant Stag Beetle
A hardy, long-lived stag beetle native to Southeast Asia's islands, known for striking regional variation across Java, Sumatra, Borneo, and Mindanao populations — a good pick for first-time keepers.
7 things to know before welcoming a Ritsema's Giant Stag Beetle
1Island-by-Island Variation
Body shape and jaw form differ noticeably between populations from Java, Sumatra, Borneo, Mindanao, and other islands. Beetles are often sold under their island origin, so checking this before buying helps you find the look you want.
2Keep Adults Separately
Males should never share a case, and males and females should also be kept apart except when pairing them to breed. Housed together, they can grab each other's jaws or legs and cause injury.
3Hardy and Easy to Keep
This species tolerates temperature swings and minor lapses in care better than many stag beetles, making it a beginner-friendly choice. Even so, avoid extreme heat and humidity and keep the enclosure somewhere with good airflow.
4Adults Live 2-3 Years
Adults typically live two to three years, giving you plenty of time to watch them through the seasons. They slow down noticeably in winter, which is usually just normal overwintering behavior rather than a problem.
5Larvae Need Mat or Bottles
Larvae are raised on insect mat or in fungus-inoculated bottles. Growth varies with food quality and individual genetics, and adults range from 28.2 to 79.0mm in males and 29.3 to 41.5mm in females.
6Handle the Jaws Carefully
Males in particular have strong mandibles that can pinch hard enough to hurt. When handling them, hold the body from the side and keep your fingers away from the jaws' range of motion.
7Prep Your Setup First
Having a calm, ready environment for your beetle from day one makes a big difference. Set up the enclosure, insect mat, a climbing branch, and insect jelly for feeding before your beetle arrives.
Frequently asked questions about Ritsema's Giant Stag Beetle
- Q.Is this a good stag beetle for beginners?
- A.Yes — it's considered beginner-friendly among giant stag beetles thanks to its hardiness and long lifespan. Following basic temperature and humidity care is usually enough to keep it thriving.
- Q.Why do individuals look different by origin?
- A.It's spread widely across Southeast Asian islands like Java, Sumatra, Borneo, and Mindanao, and each population evolved its own distinct look. That's why beetles are commonly sold under their island of origin.
- Q.Can males and females be housed together?
- A.Generally no — they should be kept in separate cases except when pairing them to breed. Housing them together risks injury from grabbing each other's jaws or legs.
- Q.How long do adults typically live?
- A.Adults generally live around two to three years. They become sluggish in winter, which is usually normal overwintering behavior rather than a sign of illness.
- Q.How much does adult size vary between individuals?
- A.There's a wide range — males run from 28.2 to 79.0mm and females from 29.3 to 41.5mm, depending on sex, origin, and how the larvae were raised.
Useful tools for Ritsema's Giant Stag Beetle care
Learn more about Ritsema's Giant Stag Beetle in the encyclopedia
View Ritsema's Giant Stag Beetle encyclopedia entry →
Care difficulty, lifespan, size and diet — all basics covered.
More in this category
Can't find the one you're looking for?
Post your wishes for free and breeders with matching animals will contact you with introductions.