Recovery of Screwworm 1 Flies Released at Various Distances and Directions of the Attractant Swormlure-2 2

Abstract

Sterile screwworm, Cochliomyia hominivorax (Coquerel), flies dye-marked and released 50 m upwind and at both sides crosswind of the screwworm chemical attractant swormlure-2 were captured at rates of 13.3, 27.4, and 14.3%, respectively, of those released the same distance downwind of the attractant, indicating that flies moved in all directions immediately after release. When released at 9 distances, 50–350 m downwind of the attractant source, recaptures of flies released 50–125 m were initially high but decreased rapidly. Recaptures of flies released 150–350 m downwind of the chemical attractant were initially low and remained ca. constant. Flies released at 150 m and beyond, apparently first dispersed at random from the release point and then were captured only after entering the odor plume. It was inferred that the odor plume or instantaneous area of influence of swormlure-2 for detection and attractancy by sterile screwworm flies extended 125–150 m downwind of the attractant source.