Developing targets to control multiple pest fly species: violet polyester targets effectively attract tsetse...

Tsetse (Glossina spp.), stable (Stomoxys spp.), and house flies (Musca domestica L.) impact humans and animals through bites and/or disease transmission. Tsetse are controlled using insecticide-coated fabric targets that are traditionally blue and/or black, but a violet polyester has now been engineered for greater attractiveness. Here, we investigate whether violet targets are also effective against stable and house flies. We sampled flies by electrocution at 1.0 (H) × 0.5 m (W) targets in Kenya, comparing catches at violet targets, and blue and black targets made from polyesters used in commercial traps and targets. Catches of female but not male Glossina pallidipes (Austen) were significantly greater at violet and black than at blue. Catches of Stomoxys calcitrans (L.), S. niger niger (Macquart), and Musca domestica were significantly greater at violet than at blue or black. Blue was significantly preferred over black for Stomoxys spp., and black over blue for M. domestica. Thus, violet targets were individually or jointly most effective against all species investigated. Catches of Stomoxys spp. and M. domestica were significantly greater at larger (1.0 × 0.5 m and 1.0 × 1.0 m) than at smaller (0.25 × 0.25 m and 0.5 × 0.5 m) violet targets. There were no significant effects of horizontal or vertical orientation for 1.0 × 0.5 m violet targets but catches of Stomoxys spp. tended to be greater with horizontal orientation, and catches of M. domestica greater with vertical orientation. Our results suggest that simple violet targets can be effective against multiple pest fly species.