It's really simple to breed SW.
1) Pump your SW's up to a good size.
2) Find somewhere that's heated / hot (higher success rate at 28-30 celsius)
3) Put the SW's individual in film canisters or pill boxes
4) Leave them in the dark for 2-3 weeks
5) Extract your Beetles and put them in seperate tank
6) Feed your beetles with fruits / veggies etc & make sure your bedding stays dry.
7) Tada, extract your SW"s every month. Just a guestimate...30 beetles should produce more than 800 -1000 a month.