The use of long-lasting insecticide netting to prevent dispersal of stored product insects

Abstract

The lesser grain borer, Rhyzopertha dominica, and red flour beetle, Tribolium castaneum, are two notorious primary and secondary pests of stored products. Extensive research has been done to prevent the establishment and subsequent infestation of the insects in stored product facilities. Long-lasting insecticide netting (LLIN) on mosquitoes has proved effective in controlling the spread of malaria, but little research has been conducted on the LLIN’s behavioral effects of stored product insects. In this study, a movement and dispersal assay were performed. In the movement assay, the video-tracking software, Ethovision, recorded the movement of R. dominica and T. castaneum after 1-10 min exposures to LLIN or control netting and a waiting period of 1 min, 24 hr, 72 hr, or 7 days after netting exposure. In the dispersal assay, R. dominica and T. castaneum were observed after 5 minutes of exposure to LLIN or control netting to measure the insects’ ability to reach new food patches at three different distances. The results from the movement assay showed a significant reduction in horizontal movement and significant increase in angular velocity for beetles exposed to LLINs, indicating that movements were more erratic and less directed. The dispersal assay revealed that exposure to LLIN had a significant effect on the dispersal ability of both R. dominica and T. castaneum with averages of 0-3 from a group of 20 beetles reaching the new food patch. These results indicate that LLINs can be an effective tool for the prevention of stored product insect establishment and colonization.

Keywords

• polyethylene netting
• integrated pest management
• behavior
• sublethal effects
• bed nets