The beetle is probably a mealworm that went through metamorphosis and transformed into it. You could keep it in its own container filled with oats, wheat, etc with other beetles and hopefully hatch some mealworms.
There are many sites (as well as threads here) that go into detail about breeding mealworms. It takes alot of time and patience but it can be done successfully. Search here and on Google for "Breeding Mealworms" and you should find enough info to get you started.
You can breed them if you want...just thought a quick solution would be to throw it out . Here's a link that was given to me before about breeding them, I am hoping to try this myself someday soon. http://www.sialis.org/raisingmealworms.htm#dead
Just some advice-- The cooler you keep them, the longer it'll take for them to breed, pupate, etc. so if you keep them around 75* you should get results faster.