IPM Bottom Board Screened Bottom Board. Designed to aid in your integrated pest management program. The Varroa Mite falls off the bee and falls through the screen to the ground and dies, thereby reducing the population of mites in the hive. A removable plastic sheet allows you to count the mites when in place. Sheet should only be in place when you are monitoring mites. The added ventilation from the screen increases brood production in the hive HP115 IPM Bottom Board..................................$16.95