How do you make your own substrate for larvae food?

I am originally from Korea, where it was so easy to buy prepared substrate for beetle larvae food. I live in the U.S. right now, and I find it very difficult to get substrate. I saw an article online where it talks about how to make your own substrate:

1) Get 100% oak wood pellets (usually used for BBQ) and flour

2) Add enough water to pellets so the solid pellets become like liquid (but not too much water)

3) Mix it with flour and store it in a cool,dark area

4) If succeeded, it should smell like old wine

I tried it but it doesn't smell like old wine at all. I am not sure what went wrong. Also, I see that "Bugs in Cyberspace" sells substrate, but I think it is VERY VERY expensive. So can anyone share their tips please?

 
According to my experience, the smell could be different depending on what you add in there. Some BBQ pellets do have strong smell then the others too.

One way to see if its working is...the heat.

Does the substrate feel warm to you? if not, maybe you should add some yeast.

 
Yeah, I've used the sawdust method, it works really well, never smelled like wine to me though. You are supposed to mix in the wood with flour and yeast, the yeast is pretty important to the whole fermenting process.

 
According to my experience, the smell could be different depending on what you add in there. Some BBQ pellets do have strong smell then the others too.

One way to see if its working is...the heat.

Does the substrate feel warm to you? if not, maybe you should add some yeast.
Thank you very much for your reply. I have three questions:

1) Which brand BBQ pellets do you prefer?

2) My substrate does not feel warm at all. I did not include any yeast yet. How long does it take to heat up?

3) What would be good ratio for pellets, flour, and yeast?

 
Yeah, I've used the sawdust method, it works really well, never smelled like wine to me though. You are supposed to mix in the wood with flour and yeast, the yeast is pretty important to the whole fermenting process.
Oh okay. I haven't added yeast yet.

What would be a good ratio for wood, flour, and yeast?

 
I used 1 cup of flour and one small packet of yeast for 10 cups of sawdust, and it worked out fine.

 
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Mine has never smelled like wine--I suspect that such a smell only occurs when the right yeasts are the dominant microbes in the production of your substrate. I just waited until my substrate was the right color, was no longer producing heat, and no longer smelled like something was rotting and spoiling.

 
Mine has never smelled like wine--I suspect that such a smell only occurs when the right yeasts are the dominant microbes in the production of your substrate. I just waited until my substrate was the right color, was no longer producing heat, and no longer smelled like something was rotting and spoiling.
What color would be considered "the right color"? When would it start heating since the process starts?

 
What color would be considered "the right color"? When would it start heating since the process starts?
When it turns from a light yellowish brown to a dark, dirt brown, it should be ready.

Here's some fermented substrate:

Moxywood%25233.JPG


 
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Yeah, I've used the sawdust method, it works really well, never smelled like wine to me though. You are supposed to mix in the wood with flour and yeast, the yeast is pretty important to the whole fermenting process.
Really? My fermenting wood smells just like a vat of wine.

 
Saw this topic decided to chip in a bit:) hope it will be helpful

1) when you "dissolve" your pellets, make sure that sawdust in the end will be just wet, but not dripping when squeezed by hand

2) your substrate may smell wine or vinegar only in the beginning, when yeasts ferment sugars in the substrate.

yeasts themselves do not ferment wood - they create good feeding ground for other microorganisms "fermenting" wood

3) During process of fermenting, correct smell should be close to ammonia smell- very nasty old socks smell, due to release of nitrogen-rich compounds. This smell could be very weak at lower temperatures or in smaller volumes.

5) Fermenting occurs much faster at higher temperatures like at least 25C. Normally it may take from 1 to 4 months to make such substrate, although it could be a bit faster when using automatic gadgets such as Japanese composters:)

6) Correct smell in the end should have mild earthy smell- no smell of vinegar or wine. If you have smell of vinegar or wine, it means that yeasts still working and compounds that produce both smells are not good for the larvae

Here I wrote this topic about substrates, which could be useful

http://beetlesaspets.blogspot.co.uk/2015/06/a-brief-and-hopefully-comprehensive.html

cheers

 
Last edited by a moderator:
Saw this topic decided to chip in a bit:) hope it will be helpful

1) when you "dissolve" your pellets, make sure that sawdust in the end will be just wet, but not dripping when squeezed by hand

2) your substrate may smell wine or vinegar only in the beginning, when yeasts ferment sugars in the substrate.

yeasts themselves do not ferment wood - they create good feeding ground for other microorganisms "fermenting" wood

3) During process of fermenting, correct smell should be close to ammonia smell- very nasty old socks smell, due to release of nitrogen-rich compounds. This smell could be very weak at lower temperatures or in smaller volumes.

5) Fermenting occurs much faster at higher temperatures like at least 25C. Normally it may take from 1 to 4 months to make such substrate, although it could be a bit faster when using automatic gadgets such as Japanese composters:)

6) Correct smell in the end should have mild earthy smell- no smell of vinegar or wine. If you have smell of vinegar or wine, it means that yeasts still working and compounds that produce both smells are not good for the larvae

Here I wrote this topic about substrates, which could be useful

http://beetlesaspets.blogspot.co.uk/2015/06/a-brief-and-hopefully-comprehensive.html

cheers


It indeed smells like a nasty ... much like a bathroom that hasn't been cleaned for months lol. Should I assume that it is fermenting correctly?

 
It smells a lot nastier if it's too wet and getting anaerobic or if you're not mixing it frequently enough. Remember: as sugars are broken down, water is produced--it will only get more and more wet if you're keeping the container from losing moisture through evaporation. You only want the initial mixture to be barely damp--if you squeezed a handful you shouldn't produce any drops of moisture.

 
Just a quick question. Hoping to get some input from those more experienced.

Earlier in the year, I prepared to make some substrate for Allomyrina dichotoma L3 grubs. I bought organic potting mix, containing no "plant food" as the main additive. I collected loads of white rotten wood from either an oak or beech stump from Georgia and added a fair amount to the soil. I didn't exactly know what I was purchasing at the time and ended up buying a compost starter. That's what I'm kinda worried about.

This compost starter reeks of salty chicken feces, as that is one of the ingredients. On the bag, it says it is to be used to start making a compost heap; it will help to break down organic material. I only added a bit to my substrate. But then again, I've had the two grubs die on me, at separate times months apart, not even making it to pre-pupas. The product is made from bone meal, feather meal, and processed poultry manure. It also contains a bunch of different species of bacteria. Other things to note - 4% nitrogen, 4% phosphate, 8% calcium, 1% sulfur.

Any thoughts? Thanks.

 
You don't want to use store-bought potting mix and compost, since its ingredients vary greatly depending on where you're purchasing it from. This means it can be composed of plant matter with the wrong nutritional components or made of plants that have natural chemical defenses. It can also contain plant matter from agricultural plant waste and may have residual chemicals or their derivatives from whatever was used in growing the plant material.

There is no reason to use compost starter or anything that contains feces of unknown origin. You don't know what those animals were fed and what was in their feed and you certainly can't guarantee the microbial life found in those feces are not pathogenic to your pets. In fact, many natural fertilizers add bacteria and fungi known to be detrimental to the health of perceived pests in order to naturally improve the health of your plants.

From personal experience, I just avoid using anything produced with the purpose of growing plants unless it's been tested and found to work. For example, many people in the eastern states do use compost and potting soil in their mixes and it works, but it's usually because they live in an area where most of the trees that go into the substrates are non-aromatic hardwoods. Here in California, we tend to have compost composed of trees like pine and eucalyptus since those are two of the most common trees that frequently need trimming or removal. Neither are suitable for rearing most species and my attempts are rearing beetles with local compost and soils have always met with failure.

 
Thanks for the feedback. I think the potting soil might be okay though. "This product is formulated from sphagnum peat moss, processed forest products, coir, organic fertilizer (see below), and yucca... Derived from poultry litter, feather meal, meat meal, and blood meal. This product contains 0.173% slowly available nitrogen from poultry litter, feather meal, and meat meal."

I live in south Florida meaning that the "soil" here is primarily made up of sand and would most likely be unsuitable for exotic grubs. So making substrate from my environment would not be a good idea. What would be the most safe alternative if "potting soils" are generally unreliable? Thanks.

 
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