Phenylacetaldehyde was tested by itself in 1965 and with the female cabbage looper sex pheromone in 1971 to obtain additional data on its attractancy to Tichoplusia ni (Hübner), and other lepidopterous species. Phenylacelaldehyde has been previously reported to be lightly attractive to male and female cabbage looper moths. The present tests showed extreme variation in its attractiveness to females, and its attractiveness 10 males could not he ascertained precisely because of the presence of live females (captured) in the traps. Addition of phenylacetaldehyde to the pheromone traps enhanced the total catch. Screen-cage traps were more efficient than were can-type traps in catching moths.