It has been used in many countries for the last 15 years. Simply hang two strips per brood chamber between frames. Leave the strips for 42 days and remove. Apivar is most effectively used before the honey flow or after honey supers are removed. Honey supers remain off the hive during the 42 day treatment period and for 14 days after strips are removed. Be sure to read and follow all label directions for Apivar. Treatment is not recommended unless you know that your varroa mite count in excess of the treatment threshold.
Note: Please call to check expiration dates if you will not use all of your Apivar immediately. The manufacturer has not been able to supply a long dated product.
For information on checking for mites, see Randy Oliver's website, www.scientificbeekeeping.com, for mite sampling methods and thresholds.