Fermented Flake Soil versus Naturally Rotted Oak

[Nathan]

What are your opinions on this?

I'm relatively new to rearing beetles, but I had excellent success with my first batch of D. tityus using rotted Red and White Oak I gathered from the woods. Besides the compost and leaves I did use some other additives. I'd like to try fermenting clean oak saw dust this Summer just to see if I get better results. Is one method better than the other?

Attached is a photo of the type of rotten oak I've been using. After mixing the leaves and compost with the ground oak the wood turns black.

 

[DynastinaeLucanidae]

I wouldn't say that one is better than the other since both methods will have their own pros and cons respectively. Maybe you could look into the type of substrate that the larvae prefer to feed on based on their species. Some may prefer flake soil made from decayed oak woods that are collected, some may prefer flake soil made from oak pellets that have undergone fermentation.

 

[Nathan]

I wouldn't say that one is better than the other since both methods will have their own pros and cons respectively. Maybe you could look into the type of substrate that the larvae prefer to feed on based on their species. Some may prefer flake soil made from decayed oak woods that are collected, some may prefer flake soil made from oak pellets that have undergone fermentation.

Thanks. I guess my question should've been has anyone reared Dynastes species using these two methods and found one to yeild better results than the other. I'm messing with D. tityus now simply because I have easy access to wild adults for rearing stock.

 

[Shade of Eclipse]

The wood in your picture is not white-rot wood. White rot mostly leaves behind a collection of stringy fiber since the process primarily uses lignin. What you have looks like either brown-rot or soft-rot wood. Brown rot and soft rot mostly leaves behind hard and powdery lignin since it's primarily cellulose being broken down. Cellulose is a sugar and can be broken down by beetles. Lignin is indigestible by animals such as beetle larvae.

 

[Nathan]

The wood in your picture is not white-rot wood. White rot mostly leaves behind a collection of stringy fiber since the process primarily uses lignin. What you have looks like either brown-rot or soft-rot wood. Brown rot and soft rot mostly leaves behind hard and powdery lignin since it's primarily cellulose being broken down. Cellulose is a sugar and can be broken down by beetles. Lignin is indigestible by animals such as beetle larvae.

So if I understand correctly, at least Dynastes would do best in a sub. using what is in the photo. That's what I've been using. I suppose there are many more variables affecting the collected wood's nutritional value compared to the fermented flake.

 

[DynastinaeLucanidae]

Well it's not safe to assume that all Dynastes could do well in the substrate that is pictured above. It may apply to your D. tityus but may not apply to other species within the genus. You're right on the variables affecting the fermented substrate, just as well as other variables affecting naturally collected decayed oak woods too. The variables are the microorganisms that decompose the wood.

 

[Shade of Eclipse]

Beetle larvae rely at least partly on gut microbes for digestion. Digestion of lignin would definitely require microbial action.

If the larvae and the right microbes for the job are not compatible, then the substrate would not be usable. The same would happen if the right microbes are not present. Sometimes that bacteria is present in the environment or in the substrate, but other times it's only supplied in the fresh frass.

For example, there are wood-feeding cockroaches that need to feed on the frass of adults after each molt in order to re-colonize their gut biome. They lose their gut microbes with each molt, so they have to have a source of microbes to regain the ability to digest their food. Some microbes simply cannot survive in the environment either due to incorrect conditions or because they are out-competed by other organisms.

 

[Nathan]

Beetle larvae rely at least partly on gut microbes for digestion. Digestion of lignin would definitely require microbial action.

If the larvae and the right microbes for the job are not compatible, then the substrate would not be usable. The same would happen if the right microbes are not present. Sometimes that bacteria is present in the environment or in the substrate, but other times it's only supplied in the fresh frass.

For example, there are wood-feeding cockroaches that need to feed on the frass of adults after each molt in order to re-colonize their gut biome. They lose their gut microbes with each molt, so they have to have a source of microbes to regain the ability to digest their food. Some microbes simply cannot survive in the environment either due to incorrect conditions or because they are out-competed by other organisms.

Thanks. I was aware of the whole gut microbes thing and always include old sub with frass in a sub change. The tityus are apparently well suited for the sub I'm using so I'll just continue with it. I'll experiment with fermenting oak saw dust eventually to see if it works better.