Effectiveness of the ZeroFly® storage bag fabric against stored-product insects

The ZeroFly® Storage Bag is a woven polypropylene bag (PP) that has deltamethrin incorporated in its fibers, and represents a novel approach to reducing stored-product insect pest-related postharvest losses. Fabric samples from ZeroFly bags, polypropylene (PP) bags, jute bags, malathion-treated PP bags, malathion-treated jute bags and GrainPro bags were affixed to the bottom of 9-cm Petri dishes and 20 adults of either Sitophilus oryzae (L.) or Tribolium castaneum (Herbst) were introduced to determine contact sensitivity of insects exposed to ZeroFly bag fabric. Knockdown, mortality and number of progeny were recorded for different exposure periods (24, 48 or 72 h) and oviposition periods (7, 14 or 21 d). Additionally, mini bags were made from ZeroFly bags, PP bags, laminated PP bags and jute bags, and used to determine ability of adult S. oryzae, T. castaneum and Rhyzopertha dominica (F.) to chew through the bags and efficacy of ZeroFly bags at preventing insect infestations from outside and to contain infestations within bags. Knockdown assessment for ZeroFly bag fabric showed that time required to knockdown 99% of S. oryzae and T. castaneum was <3 h. For 72-h exposure to ZeroFly bag fabric, mortalities for S. oryzae and T. castaneum were 76.7 and 62.2%, respectively; mortality was ≤6% in other fabrics. ZeroFly bag fabric also significantly suppressed progeny production by S. oryzae and T. castaneum for all exposure periods. No insects from the three species tested were able to chew through miniature ZeroFly bags, indicating the bag fabric will prevent entry or exit of insects.