APIGUARD active ingredient is thymol. Thymol in a slow-released gel is used to control varroa mites in trays. It is best applied in the fall with temperatures between 59 and 100 degrees. Do not treat with honey supers on the hive. The trays are placed in the hive according to leaflet instructions, repeated after 2 weeks and left in place for another 2 weeks. Average efficacy is 93%. Read full manufacturers instructions. Sold by single tray.