One single application has efficacy up to 99% and there are no temperature constraints as there are with MAQS and other products. It can be used at any time of year (supers must not be on the hives). The strips are left in for between 6 and 10 weeks depending on the size of the brood.
Not to be confused with Apitraz, which is a totally different formulation and has a shelf life of only 12 months. Apivar has a shelf life of 24 months. More information here