If you have trouble finding red rot wood, I would recommend using very fermented wood/plant substrate. Treat it as a rhino beetle and keep the substrate slightly damper than you'd usually do. I don't have experience with this species but others in the genus and surrounding locality do well with this setup.
As for mating them, wild collected females are almost always fertilized. But if you have a healthy male, there is no reason not to mate them again to make certain of that. Keep both adults well fed for a few days. Stop feeding the female for one day to keep her slightly hungry but keep feeding the male. The next time you feed the female, she will concentrate on eating. Place the male on her back or in her proximity and they should start mating. You might want to do this on a log or some other surface that they have a firm grip on. It helps with them positioning themselves when mating. Just keep an eye on it as they do their business, keep tools on hand if you need to separate them. Do not leave them together without watching them. If all goes well, this should be done within 10-20 minutes, and they should be separated afterwards.