| dc.description.abstract | The ZeroFly� Storage Bag is a deltamethrin-incorporated polypropylene (PP) bag, and is a novel tool used to reduce postharvest losses caused by stored-product insect pests. Data on the effectiveness of ZeroFly bags in preventing damaging insect infestations is critical for the scale-up of these bags in the developing world. Therefore, this study investigated response by adults of Sitophilus oryzae, Tribolium castaneum, and Rhyzopertha dominica to different concentrations of deltamethrin, 1, 25, 50, 100, 250, 500, 1000, and 3000 ppm over two exposure periods, 24 or 48 h. Deltamethrin was highly effective, achieving 99% knockdown of insects of all species within 4 h after exposure at concentrations ? 25 ppm. LC95 values for these pests, for the 48-h exposure period, were ? 3,000 ppm, the concentration of deltamethrin in new ZeroFly bag fabric. Experiments were also conducted to measure the sensitivity of insects in contact with fabric of ZeroFly bags, PP bags, jute bags, malathion-treated PP bags, malathion-treated jute bags, and GrainPro� bags ? data for time to knockdown, mortality, and number of progeny of S. oryzae and T. castaneum were collected. Times to knockdown of 99% of insects were ? 3 h; in the 72-h exposure period, mortality of S. oryzae and T. castaneum was 76.7 and 62.2%, respectively, for the ZeroFly bag fabric. Relative to other fabrics, ZeroFly bag fabric significantly suppressed progeny production by S. oryzae and T. castaneum at all exposure periods. Evaluation of miniature ZeroFly bags showed that none of the insects were able to bore (chew) through the bag. Although no insects gained entry into PP bags or laminated PP mini bags, mortality of insects in these mini bags was significantly lower than in ZeroFly mini bags. The field study conducted in the Middle Belt of Ghana showed that ZeroFly bags are more effective than PP bags in terms of reducing insect populations, insect damaged kernels, and percent weight loss. Results indicate that the ZeroFly bags can be highly effective in protecting grain for long-term storage, if insect-free grains are stored in them. | |
