Dadant Wood Bound Varroa Screen. Mites fall through screen onto bottom board. When used with a sticky board, this makes a trap that will eliminate all mites that fall onto it. If more than 100 mites are caught within 48 hours, a chemical treatment may be needed. Contact your state apiarist for guidelines.Researchers have found that as many as 40% of live young Varroa mites simply fall to the bottom of the hive, then crawl back up looking for a honey bee to begin feeding on. Catch those mites to eliminate them and also be able to answer two important questions: 1.) Do I need to treat with chemicals?, or 2.) Did the chemical treatment work? (buy BeeWeaver Queens and avoid chemicals!) Make your varroa trap with either the Dadant Wood Bound Varroa Screen and Sticky Board, or the Phero-Tech Screen and Sticky Board.Bottom board shown in white not included. *May not fit all bottom boards.