Control of Hornworms1 by Trapping with Blacklight and Stalk Cutting2 in North Carolina

Abstract

Studies were continued in 1963 and 1964 near Oxford, North Carolina, to determine the effectiveness of a combination of traps equipped with blacklight lamps plus stalk cutting for large-area control of the tobacco hornworm, Manduca sexta (Johannson), and the tomato horn-worm, M. quinque (Haworth) on flue-cured tobacco. In 1963, the numbers of eggs and small larvae at the center of the 113-square-mile study area decreased 83% compared with the numbers 6 miles outside the area. In 1964, the estimated damage from the tobacco hornworm at the center of the trapping area was 77 and 91% less than that 6 and 14 miles outside the area. Marked increases in stalk cutting in the trapping area in the fall of 1962 and 1963 probably increased the control. In 1963, 90% fewer applications of insecticide for hornworm control were made inside the trapping area than outside; in 1964, 60% fewer applications of insecticides for control of all tobacco insects were made inside the area.