In wind tunnel flight tests, only 13% of maleCampoletis sonorensis(Cameron) located a female in the absence of a cotton plant, whereas 63% of males located a female placed on a leaf of a cotton plant. Males flown to plants only in the wind tunnel zigzagged in the plume of the plant volatiles but landed infrequently. The increased mate location observed when females were located on a cotton plant was due partly to plant olfactory cues and partly to plant visual cues. Males located females 60% of the time when females were placed on plants and only 33% of the time when the plant was hidden from the male's view but plant volatiles were present. Male flight behavior is described and was distinctly different toward a female compared with a plant alone.