Use of paired and single traps to assess perception and discrimination of sex pheromone mixtures in the field byTrichoplusia ni (Hübner).

Paired wind-oriented traps (WORT) and single traps were deployed simultaneously in the same field to investigate whether or not inferences about the central nervous system processes of discrimination and perception can be made from differences in moth captures. The stimulus levels deployed were those that typically may be found downwind of a calling virgin female cabbage looper,Trichoplusia ni (Hübner), so that inferences are relevant to natural stimulus intensities. Captures of male cabbage loopers in the WORT traps paralleled prior laboratory measures of pheromone mixture discrimination. The pattern of captures by the two trapping systems probably reflects perceptive and discriminative processing differences in the central nervous system. Captures in traps baited withZ7-12: Ac alone were equal to, or better than, captures in traps baited with three- and six-component mixtures that containedZ7-12: Ac.