Conclusion and Recommendations: The different potential alternate host plants reflect the differences in host utilization capabilities of the local populations of the ACB. Whether the observed differences reflect mainly genetic diversity or reflect possible higher differences suggest that management of ACB may involve region-specific strategies. These alternate host plants may serve as natural refugia. Studies of other naturally occurring plants in the corn fields will also provide additional potential refugia for corn borer management. Further work is needed to provide insights on how these potential alternate hosts: (a) affect the concept of "refugia" in a tropical setting; (b) affect the population and behavior of ACB and its natural enemies in a Bt corn dominated field; and (c) play a significant role in an effective IRM strategy specific to tropical countries like the Philippines.