Install screened bottom boards

Replace solid bottom boards with screened versions that have a removable monitoring tray beneath a #8 hardware cloth screen. Bees chase SHB downward, and beetles and larvae that fall through the screen cannot climb back up to the comb.

Why It Works

SHB larvae drop to the bottom of the hive when ready to pupate in soil. A screened bottom board lets them fall through and away from the colony rather than crawling out the entrance and burrowing into the ground directly beneath the hive. Combined with a tray of oil below the screen, fallen beetles and larvae drown before reaching the soil.

Tips

• Add a thin layer of vegetable oil in the monitoring tray to trap beetles that fall through
• Clean the tray and refresh oil every 1-2 weeks to prevent debris buildup
• Screened boards also improve ventilation, which helps reduce the humid conditions SHB prefer
• In cold winter climates, insert a solid board beneath the screen to reduce drafts