Electroantennographic responses differentiate sibling species of dingy cutworm complex,Feltia jaculifera (GN.) (Lepidoptera: Noctuidae).

The dingy cutworm is one of the more common and widely distributed of North American noctuids. Determination of the antennal responses of field-collected male moths to a standard test blend of pheromone components shows that two pheromonal phenotypes of the dingy cutworm occur throughout the prairie region of western Canada and at least two others occur in eastern Canada. The pheromone types are morphologically indistinguishable and, so far as is known, have similar life histories and biology. The two prairie types are broadly sympatric with partially overlapping seasonal flight periods. Although hybrids can be easily produced in the laboratory, there is no evidence of hybridization in the field. The pheromone system of the dingy cutworm is apparently rather plastic, resulting in a mosaic of pheromone types (sibling species) that appear to be reproductively isolated but have not differentiated morphologically.