Odour-baited targets to control New World screwworm, Cochliomyia hominivorax (Diptera: Calliphoridae): a preliminary study

Abstract

Biconical, F3, and wind oriented (WOT) traps, and black cloth targets, baited with the odour attractant swormlure-4, were assessed as catching and killing devices for the New World screwworm fly, Cochliomyia hominivorax (Coquerel), in Mexico. Among the traps, the WOT was significantly better than the others, with a mean catch 2.7 and 86.4 times better than those of the biconical and F3, respectively. Release of swormlure-4 could be reduced from the standard 10 ml'day to 2 ml'day without a reduction in the numbers caught in a WOT. Use of electric nets demonstrated that a large visual target was not necessary for the precise location of a swormlure-4 source by C. hominivorax. Target colour was important with respect to the landing response on targets: in a two-choice situation, flies landed much more frequently on black than on blue or yellow, and more on these two colours than they did on white. C. hominivorax tend not to circle a target before landing on it: about 75% of the flies caught on a combination of electrified black target plus electric flanking net were caught on the target. The potential for use of insecticide-impregnated cloth targets in suppression of adult C. hominivorax is discussed.