Sterilizing homemade substrate: yes or no? ...and how?

Hi Everyone,

I am very excited to start keeping my first beetles, Dynastes granti. I have an empty 65 gallon aquarium sitting around, and I am going to use that.

Today, I went out to the forest and collected lots of rotting hardwood and leaves. I am also using some coco fiber as a filler, since it's a pretty big cage. I plan on getting a bag of organic compost as well.

My question is: do I need to sterilize my box of rotting wood & leaves, or are there potentially beneficial organisms in there? If sterilization is necessary, how does one accomplish this? I have heard several different methods, some contradicting with others. For example, microwaving (but times are all over the spectrum), soaking in water for up to 1 week, baking in the oven (for anywhere from 30 minutes to 2 hours, and at what temp? 250? How does this not catch on fire in the oven??)

I tried to sterilize some sweet gum balls in the microwave one time, and they caught on fire.

What do you guys do?

Thanks so much

Katie

Kansas, USA

 
hey dont do wat i do because im not professional but i think you put wood in water submerged and then heating it...

i find bunch of click beetle larvae and other weird larvae that eats stag beetle egg so i would just kill them

 
65 gallon isn't really necessary unless you have like 10+ pairs lol

Also, don't use cocofiber.

I really don't know why people bake or microwave, i think using a spade to chop them into pieces will do the job fine lol, plus if you do find any, just take them out,

 
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I have never heat treated substrate for beetle larvae... until I moved to North America.

The problem is that click beetle larvae, parasitic mites and baby centipedes can be so small that even when you chop the wood to small pieces using a spade you may still end up with some pieces harboring eggs of harmful critters.
I learned this the hard way. I kept a small colony of local millipedes for 3 years in decomposing wood substrate (the same type we use for beetle grubs) and never got to find eggs or babies. Last week I moved all my individuals and springtails to a new container with treated substrate (baked), and already found several eggs a week later. When I examined the old subsrate closely I found the problem - it was swarming with small centipedes.

 
65 gallon isn't really necessary unless you have like 10+ pairs lol

Also, don't use cocofiber.

I really don't know why people bake or microwave, i think using a spade to chop them into pieces will do the job fine lol, plus if you do find any, just take them out,
well its from the wild so it needs to be heat treated or you are risking youe eggs

 
65 gallon isn't really necessary unless you have like 10+ pairs lol

Also, don't use cocofiber....
Why should we avoid coco fiber? Perhaps that is why my girls aren't laying....
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What should I use instead?

 
Why should we avoid coco fiber? Perhaps that is why my girls aren't laying....
default_biggrin.png
What should I use instead?
cocofiber has no nutritional value for the larva. I'd suggest using organic compost instead..

well its from the wild so it needs to be heat treated or you are risking youe eggs
I remember Matt saying you really don't need to treat your substrate, as long as you chop them up into little pieces. I also think treating the sub will kill the microorganisms.

 
I use an oven, but only because I do not own a microwave.

Each has its own pro's and con's-
Microwave is faster, but its size is smaller so you can only treat a little substrate at a time
Oven is larger and can treat a nice volume of substrate, but takes more time to treat

 
Can you go into depth about how long you cook in the oven, and at what temperature? I'm hoping to get this done today. I know the coco fiber is just fill, but it's harmless, right?

 
I put the moist substrate into a heat-resistant bowl and cover with aluminum foil. I puch two small holes in the foil. I put the bowl in the pre-heated oven (180-200 degrees Celsius. Sorry, I'm not good with Fahrenheit units. Should be 400 maybe?) for 20 minutes. The fact that the substrate is moist is important - inside the oven the water vapor turns to steam and cook any living orgnism/egg hiding in the substrate. I then take the bowl out, let it cool, mix the substrate with some leaf compost and store it.

 
The problem with coco fiber is that it serves no purpose aside from being fill. It will deter the females from laying and makes the larvae work harder to get edible bits of substrate. Any coco fiber that is ingested in the process of feeding would also only take up space in the larva's gut and reduce the amount of nutrients the larva gets from feeding. Depending on the location that the coco fiber was harvested, it may also have varying amounts of salt which would further decrease the appeal of the substrate. Coco fiber has no useful application in keeping and rearing Dynastes granti.

 
You're not trying to sterilize the substrate, you're only trying to kill the worms and other invertebrate pests so if you can get it to a thorough 120F for a time it's hot enough. You might be able to set an oven that low but it would probably require quite a few hours unless the layer were very thin. Even if you could or were trying to sterilize the substrate the larvae would reinfect it with bacteria and mold.

 
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