Montanellus Long-jawed Stag Beetle

Montanellus Long-jawed Stag Beetle key facts

Care level

Advanced

Lifespan

Adults 4-6 months (typical for the genus)

Size

Males 22.7-79.0 mm (wild record 79.0 mm; the captive record is 76.2 mm)

Diet

Beetle jelly (in the wild it visits flowers of herbaceous plants)

Temperature & Humidity

This is a montane species and breeders report that it likes cool conditions. Cyclommatus above all dislike stale humid air, and condensation inside the box shortens life. Keep it cool and out of direct sun, with newspaper or a well-perforated sheet under the lid for ventilation.

Breeding & Egg-laying

Soak a soft log of oak or similar, about 10 cm across, for two hours to a day and strip the bark. Pack 3-5 cm of fine-grained fermented substrate hard in the base, lay the log on it and bury it completely. A female in good condition lays 20-30 eggs. Collect the larvae early, because they cannibalise each other if left too long.

Cohabitation

Keep singly. Hand pairing works once the beetles are mature and mating is easy; the female is far smaller than the male but pairs without trouble. The genus is fairly placid, but females are occasionally killed, so move the male to his own container once mating is confirmed.

Lifespan & Rearing Period

Adults live about four to six months and larger males live longest. Larvae take three to six months for females and three to ten for males. In this species females tend to pupate well ahead of the males, so the sexes emerge badly out of step. Feeding starts two to five weeks after emergence.

Health & Notes

Fungus bottles are unsuitable and larvae die in ordinary mycelium. Pack fermented substrate to 80-90 per cent of the container and change it every two to three months. Within Cyclommatus, the high-altitude species are the hard ones to get eggs and larvae from, so keep more than one line going.

About Montanellus Long-jawed Stag Beetle

A long-jawed stag beetle from Borneo's mountains, known for slender mandibles reaching nearly half its body length and unusually large size within its genus. This highland species prefers cool temperatures, and care is best left to experienced keepers.

7 things to know before welcoming a Montanellus Long-jawed Stag Beetle

1. 1Cool Temperatures Are Essential

   This beetle comes from the mountainous highlands of Borneo and thrives in cool conditions. It doesn't handle summer heat well, so keeping its enclosure at a stable, cool temperature is key to keeping it long-term.

2. 2Handle the Long Jaws with Care

   Its signature trait is a pair of slender mandibles that reach nearly half its body length, with wild specimens recorded up to 79.0mm. Because the jaws are delicately shaped, take care not to put stress on them when handling the beetle or rearranging its enclosure.

3. 3Breeding Across Generations Is Tricky

   The Montanellus Long-jawed Stag Beetle is known for being difficult to breed successfully across multiple generations. It's best approached step by step, building general keeping experience before attempting to breed it.

4. 4Adult Lifespan Is Relatively Short

   Adults typically live around four to six months. Since this window is limited, it's worth planning ahead for how you'll observe and care for the beetle during that time.

5. 5Suited to Experienced Keepers

   This species is rated as suitable for advanced keepers. Between the temperature demands and the difficulty of breeding, it's better suited to those who already have stag beetle keeping experience.

6. 6Size Varies Considerably Between Individuals

   Adult males range from 22.7mm to 79.0mm, with a captive-bred record of 76.2mm. Individuals with especially long jaws will appreciate a bit of extra room in their enclosure.

7. 7Prepare the Environment Before You Bring One Home

   Since this species prefers cool conditions, check beforehand whether you can keep its enclosure reliably cool. Setting up a highland-appropriate environment in advance will make care much smoother once the beetle arrives.

Frequently asked questions about Montanellus Long-jawed Stag Beetle

Q.Can beginners keep this species?

A.This beetle is rated for advanced keepers, so it can be challenging for someone new to stag beetle care. It's a good idea to gain experience with an easier species first before taking this one on.

Q.How long can I expect to keep one?

A.Adults typically live for about four to six months. It's worth factoring that timeframe into your planning, since how long you get to enjoy the beetle depends on when in its adult life you bring it home.

Q.How big do the mandibles get?

A.Adult males range from 22.7mm to 79.0mm, with wild specimens recorded up to 79.0mm. Since the jaws make up nearly half the body length, some individuals grow to an impressively large size even within their genus.

Q.Is it easy to breed across generations?

A.No — this species is known for being difficult to breed successfully across multiple generations. If you want to try, it's best to research thoroughly first and proceed carefully.

Q.What should I watch out for in its environment?

A.As a highland species that prefers cool temperatures, careful temperature management is especially important during summer. Check in advance whether you can keep its enclosure reliably cool.

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