Beetle Grub composting

[willow]

So have been researching worm castings. As an organic source of all good things that my peppers can eat up and I have read its a good source of usable calcium which is something I could do with. So in my research I have read it can be hard for the worms here as it gets too hot, makes sense as I have never seem worms in my compost. That said I have heard stories of people doing it so it can be done.
 
That aside I read today of someone using beetle grubs as an alternative here in Panama. Now it just so happened to day my and my groundsman turned over our toilet paper compost. W must have pulled out about 30 of the grubs in the pic below, not my pic though (fed them to the chickens so expecting some big eggs over the next week). They were about 3 inches long! Huge and fat, absolutely loving the compost and they have done a great job in breaking it down. I estimate there must be about 1-200 in the compost.
 
So my plan is to build a grubbery, has anyone had any experience with such? From what I can tell they pretty much do the same job and produce the same nutrient rich poop as compost worms. As long as I can keep them in the grubbery as they can cause havoc with seedlings of all types eating the roots, these guys eat anything organic at any stage of decomposition.