The subject invention relates in part to Cry3Aa in combination with Cry6Aa. The subject invention relates in part to the surprising discovery that combinations of Cry3Aa and Cry6Aa are useful for preventing development of resistance (to either insecticidal protein system alone) by a corn rootworm ( Diabrotica spp.) population. Included within the subject invention are plants producing these insecticidal Cry proteins, which are useful to mitigate concern that a corn rootworm population could develop that would be resistant to either of these insecticidal protein systems alone. Plants (and acreage planted with such plants) that produce these two insecticidal protein systems are included within the scope of the subject invention. The subject invention also relates in part to combinations of Cry3Aa and Cry6Aa proteins "triple-stacked" or "multi-stacked" with another insecticidal protein(s) such as a Cry6Aa protein or binary Cry34/35 proteins. Thus, such embodiments target rootworms with three modes of action. Transgenic plants, including corn, comprising a cry6Aa gene and a cry3Aa gene are included within the scope of the subject invention.