Glossary
A commercial varroa mite treatment consisting of plastic strips impregnated with amitraz, a contact acaricide. Apivar strips are placed in the brood nest where worker bees contact the strips and spread amitraz throughout the hive through their normal movement. Treatment duration is typically 42-56 days for maximum effectiveness.
Amitraz, the active ingredient in Apivar, affects the octopamine receptors in varroa mites, causing hyperexcitation, detachment from the host bee, and death. Importantly, honey bees have a different octopamine receptor structure than mites, making amitraz selectively toxic to varroa while relatively safe for bees at treatment concentrations.
Apivar strips are placed between frames in the brood nest, two strips per brood box, for a treatment duration of 42-56 days. This long treatment period is necessary to expose mites that emerge from capped brood cells throughout the brood cycle. Strips should be in direct contact with the bee cluster to ensure adequate amitraz distribution.
Apivar cannot be used when honey supers intended for human consumption are on the hive. This limits its use to early spring (before honey supers are added) and late summer/fall (after honey supers are removed). Planning the beekeeping calendar around treatment windows is essential.
Amitraz resistance has been confirmed in varroa mite populations in some parts of the United States. Beekeepers should monitor treatment efficacy (measure mite levels before and after treatment) and rotate between different treatment classes (amitraz, organic acids, thymol) to slow the development of resistance.
The most common treatment windows are early spring (March-April, before honey supers go on) and late summer (August-September, after honey harvest). The late summer treatment is the most critical because it protects the winter bee generation from mite damage.
Amitraz breaks down relatively quickly and does not accumulate in wax the way older miticides (coumaphos, tau-fluvalinate) did. However, Apivar should never be used with honey supers in place. When used according to label directions, residues in subsequently produced honey are negligible.
When mite populations are susceptible, Apivar achieves 90-99 percent mite kill over the full treatment period. However, confirmed amitraz resistance in some regions can significantly reduce effectiveness. Always verify treatment success with a post-treatment mite count.
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