Certain species of trees and tree-based commercial mulches support higher termite colony growth and survival rates than other tree species. The large-scale use of tree-based mulches in landscapes may inadvertently contribute to local establishment and growth of the Formosan subterranean termite, Coptotermes formosanus (Isoptera: Rhinotermitidae). In practice, cultural control is a very important component of IPM of subterranean termites, which involves creating an undesirable biological and ecological environment for termite colonizing, tunneling, feeding and spreading. Thus, this research reported a promising improvement in resistant properties of tree-based landscape mulches against C. formosanus (Isoptera: Rhinotermitidae) when mulch substrates were treated with a strain of the termite fungal pathogen, Metarhizium anisopliae. The laboratory results indicated that mulches treated at >105 fungal conida/ml could significantly suppress foraging termites and affect their tunneling and feeding behaviors.