The Varroa mite has presented quite a challenge to beekeepers throughout the USA. Left untreated, you will lose your hive. Apiguard is a Thymol gel, used to control Varroa mites. Each hive gets two treatments, 10-14 days apart, and works best when daytime temperatures are above 60 degreesThis box contains ten single-treatment trays. F. Note: Never medicate when there is honey on the hive for human consumption.