The Mexican rice borer, Eoreuma loftini (Dyar) (Lepidoptera: Crambidae), is one of the most important pests of sugarcane, Saccharum officinarum L., in Mexico, but the population dynamics of the adult are not known for conditions in the state of Morelos. During the 2013 season, 11,282 adult males were caught, with the largest number of adults trapped on the eastern and western sides of the state. Two population peaks were observed, the first during the dry season (February-June) and the second during the rainy season (October- December). Implementing monitoring of this stalk borer as part of an integrated pest management program is discussed.