Cabbage Looper: Populations in BL Traps Baited with Sex Pheromone in Florida, Georgia, and South Carolina

Abstract

Adult populations of Trichoplusia ni (Hübner) were investigated at 19 locations in Florida, Georgia, and South Carolina using BL traps baited with synthetic sex pheromone, Z-7-dodecen-1-ol acetate. Three geographic zones were established on the basis of adult catches: northern zone in which average winter temperatures are below 10°C, there is no adult activity during winter, and populations do not reach significant levels until mid-summer; intermediate zone consisting of northern Florida, the Georgia coastal plain, and the lower coastal plain of South Carolina in which average winter temperatures fall between 10–16°C, adult activity is very sporadic during winter, increases sharply in spring, and continues significantly until fall; southern zone consisting of peninsular Florida in which average winter temperatures exceed 16°C, adult activity is significant throughout the year, being greater in late winter and spring, and decreasing in summer. Continuous reproduction and development during winter occur only in the southern zone. Minimum winter temperatures in this zone correspond to minimum temperatures for larval development, mating, and flight. Adult movement northward outside the overwintering zone follows the advancing 16°C temperature zone and indicates migration.