In the wild Rhinobeetles live inside and on decaying hardwood. Rearing the animals in captivity needs this environment to be replicated.
When it comes to breeding adults and rearing larvae you are absolutely dependent on decayed vegetation called substrate ( also called "Mat"). Adults lay eggs only in it. Larve hatch only in it. Larvae eat only substrate. Larvae pupate in it. Understanding decayed vegetation is crucial if you are planning to breed rhinobeetles.
Adult beetles are not so fussy and can be kept in much simpler and cheaper materials (see separate article for details) but larvae can only eat the decayed wood substrate - soil, bark, coia etc are all inedible. Some species will have a nibble at rotted leaves but it is not their normal food and they will not grow well.
Decayed vegetation can be divided into three types
- Material that comes from soft plants (non trees). This decays too quickly and offers no sustenance to beetles.
- Material that comes from coniferous trees, e.g. pine, cedar or cypress trees. This type of wood is not suitable for rhino beetles as it contains plant oils which are harmful and not edible by the beetles.
- Material from hardwood (deciduous) trees, e.g. oak, maple, ash, willow, birch etc. This type of vegetation is usable by rhino beetles and whenever we talk about decayed vegetation we actually mean decayed deciduous wood.
When a tree dies its wood is unusable by beetles until it has been decayed by fungi. There are 9 stages of decayed wood:
- Hard decayed wood
- Middle decayed wood
- Soft decayed wood
- Natural decayed wood flakes
- Hard decayed wood flakes
- Middle decayed wood flakes
- Soft decayed wood flakes
- Flake soil
You can make your own substrate but it can take years to perfect and it takes around a year to produce high quality substrate. Alternativly you can get high quality different types of substrate for your beetles from this us.
When to change substrate
Both adults and larva produce faeces from their food. This looks like hard lumps of substrate but when you look closely you can see it is different. If you want to be efficient and keep the expensive substrate you can just sieve out the faeces and reuse the remaining substrate. We use a simple kitchen collander - the lumps that are left behind are faeces and the stuff that goes through the collander are ok to reuse. Note dont push the material through, let it feed by gravity - if you push the material through the filter you will break up the faeces and defeat the object of the sieving.
How to fill your containers
We recommend the following procedure for our normal breeding jars.
- Half fill the container with substrate.
- Gently compress the substrate down to about 1/4 of the container (use a tamper!)
- Add more substrate up to about 1 cm from the top of the container, leaving enough room to place your larva.
- When the larva burrows it will decompress the substrate, filling the whole container.
Remember to add aeration holes in any jars you supply yourself (ours come prepared) and cover the holes with suitable gauze to stop substrate exiting or pests getting in.