Peanut beetles
(Ulomoides dermestoides)
 
This darkling beetle is not only super easy to breed and rear, it has a phenomenal nutritional profile: the average peanut beetle larvae composition is approximately 55 percent crude protein, 18 percent crude fat, 3 percent ash, and 24 percent sugars.
 
Although their common name would suggest peanuts as part of their care and propagation in truth this beetle does fine on simple wheat bran or rolled oats are perfectly sufficient to maintain a healthy and breed this beetle.