Moneilema gigas (cactus longhorn) substrate?

[PowerHobo]

I may be somewhat unexpectedly receiving some cactus longhorn beetles very soon, and am just curious if anyone has any experience with the best substrate for them. I want them to be able to breed if they choose, though I'm not counting on it. Since they eat and breed near prickly pear and cholla, I assume their preferred sub is similar to the planting needs for those cacti (1:1 potting soil and sand)?

I appreciate any helpful knowledge in advance!

 

[arizonablue]

I have three, and I'm keeping them on a mix of coir and sand, mostly sand. Mine have mated but I have not seen any eggs deposited. 

In addition to cactus, they will eat beetle jellies. They also like to climb a lot, mine spend most of their time perched at the top of a piece of cholla.