01/06/2026
Treating Varroa Without Chemical Strips
For 5 years we have not used chemical strips to treat the parasitic mite varroa. The reason for this was after in depth discussion with one of the manufacturers after noticing reduced mite drops but alcohol washes were high. This indicated a possible resistance but I questioned how critical the 15 degree constant temperature stated in the instructions were.
Varroa destructor remains the greatest threat to honey bee colonies and one of the biggest challenges to beekeepers. Failing to treat for varroa leads to a total colony collapse at around 3 years. Presented by empty hives (no dead bees) in the Spring.
One of the main limitations of strip-based treatments is that they rely heavily on bee movement within the hive. When temperatures fall below around 15°C, bees become less active and cluster more tightly, reducing contact with the strips and limiting the distribution of the active ingredient throughout the colony.
As a result, treatments applied during cooler weather may not achieve the level of mite control expected, allowing varroa populations to continue increasing. Repeated use of the same chemical products can also contribute to resistance developing within mite populations.
Alternative treatment methods can provide effective control without relying on strips. Oxalic acid vaporisation is widely used during broodless periods, as it targets phoretic mites living on adult bees. When timed correctly, it can achieve very high levels of mite mortality. Oxalic acid dribbling is another option, although it is generally used less frequently to avoid stressing colonies.
Good colony management also plays an important role. Regular monitoring through mite counts allows beekeepers to make informed decisions rather than treating blindly. Drone brood removal can help reduce mite numbers during the season, while creating brood breaks through queen caging or artificial swarming interrupts the varroa breeding cycle.
No single treatment offers a complete solution. The most successful approach combines monitoring, timely intervention and integrated pest management techniques. By reducing dependence on chemical strips, beekeepers can maintain healthier colonies and improve long-term varroa control.
While a lot of beekeepers blame weather on their losses vital vorra control is the first step to maintaining healthy be colonies.