Beanweevils (Callosobuchus maculatus)
These critters are easily kept in smaller containers with a well ventilated lid. A plastic lid with a fine metal mesh is working very fine. Add about 4cm of blackeye beans (or mung beans) in the container. Add new hatched beetles to the container and just wait. They do not need any extra feeding except from the beans, but adding some fruit will be appreciated. Just be careful since it might bring mold into the culture. One generation takes about 1 month in 27°C.
The beetles needs black eyed beans or mung beans for their sustenance. Ordinary beans contain a lecitin that is toxic for beanweevils.
You don't have to throw away the beans from the culture after they hatched. It's possible to reuse it if you sift the beans to get rid of faecals. Adding more beans is a good idea.