Bioassay of the Synthetic Female Sex Pheromone of the Cabbage Looper123

Abstract
A Y-tube apparatus was developed for quantitative bioassay of the synthetic sex pheromone of the cabbage looper, Trichoplusia ni (Hübner). When 3- to 7-day-old (inclusive) male cabbage looper moths were used, the attractive concentration for 50% response (AC50) was 1.08µg pheromone on filter paper. Based on the dissipation rate of 5µg on filter paper, the actual concentration of pheromone in the airstream at AC50 was calculated to be about 91 ng/m3 air. No increase in response was noted between 5 and 5000µg.