RESIDUAL EFFICACY OF CYFLUTHRIN EMULSIFIABLE CONCENTRATE AND WETTABLE POWDER FORMULATIONS ON POROUS CONCRETE AND ON CONCRETE SEALED WITH COMMERCIAL PRODUCTS PRIOR TO INSECTICIDE APPLICATION

Spray emulsions formulated from a cyfluthrin emulsifiable concentrate (EC) and a cyfluthrin wettable powder (WP) were applied to concrete which was left unsealed or sealed with either Waterproofing Sealer, Olympic Waterguard, or Thompson's Water Seal. At weekly intervals the concrete was bioassayed with adult Tribolium castaneum (Herbst) and adult Tribolium confusum (J.duV.) for 1, 6 and 24-h exposures each week for 14 weeks. With one exception, T. castaneum and T. confusum survival after 1 h exposure at week 1 on concrete treated with the EC exceeded 10% on all three commercial sealants and the unsealed control. At the 6-h exposure, T. castaneum survival was < 10% for 2, 2, 3 and 7 weeks on unsealed concrete, Waterproofing Sealer, Olympic Waterguard and Thompson's Water Seal, respectively; survival on each treatment at the 24-h exposure was < 10% for 2, 3, 9 and 12 weeks, respectively. At the 6-h exposure, T. confusum survival was < 10% for 2, 3, 6 and 8 weeks on unsealed concrete, Waterproofing Sealer, Olympic Waterguard, and Thompson's Water Seal, respectively; survival on each treatment at the 24-h exposure was < 10% for 4, 3, 7 and 12 weeks, respectively. When these species were exposed on unsealed concrete treated with the WP, survival decreased as exposure time increased. Except for two instances, survival after 6 and 24 h was zero for both species on all three sealants.