The sunflower moth,Homoeosoma electellum(Hulst.), is a severe and frequent pest of cultivated sunflower in Texas and other southern states. It is a sporadic pest in the north central states and in Saskatchewan. Pheromone-type traps baited with virgin female sunflower moths synthetic sex pheromone or both were placed near sunflower fields at various locations in Saskatchewan. These provided data on the arrival of migrant sunflower moths and the duration of moth flight. North American weather maps were examined for the presence of sustained, warm, southerly winds blowing from the Gulf of Mexico toward Saskatchewan. Results show that, from 1976 through 1979, one or more weather systems causing warm, southerly winds capable of transporting sunflower moths from Texas northward into Saskatchewan developed during late June or early July. Increases in the number of moths caught coincided with the arrival of the winds in one or more Saskatchewan localities. This provides strong evidence that the sunflower moths are being transported on these weather systems.