How can you treat bees with tansy for mites? - briefly
Apply a tansy extract or spray to the brood area, covering frames thoroughly and allowing it to dry before re‑capping; repeat the treatment every 7–10 days during the mite‑growth period. This method reduces Varroa populations without harming the colony when used at recommended concentrations.
How can you treat bees with tansy for mites? - in detail
Treating honeybee colonies for Varroa destructor with tansy (Tanacetum vulgare) requires careful preparation, application, and monitoring. The plant contains essential oils, chiefly thujone and camphor, that exhibit acaricidal activity when delivered to the brood nest.
Preparation of the tincture
- Harvest fresh aerial parts (leaves and flowering tops) early in the morning when oil concentration peaks.
- Chop material finely, weigh 100 g, and place in a glass jar.
- Add 1 L of 70 % ethanol, seal, and store in a dark place for 48 hours, shaking twice daily.
- Filter through cheesecloth, then dilute the filtrate with equal parts sugar‑water syrup (1 kg sugar dissolved in 1 L water) to achieve a final concentration of approximately 2 % ethanol and 0.5 % tansy extract.
Application protocol
- Ensure colonies are strong, with at least two frames of capped brood.
- Place a clean feeding tray or sugar board inside the hive and pour the diluted tincture, allowing bees to ingest it over 24 hours.
- Simultaneously, spray the interior of the brood frames with a fine mist of the undiluted tincture, avoiding direct contact with the queen and brood comb to prevent wax softening.
- Repeat the feeding and spraying cycle on days 3, 6, and 9.
Environmental considerations
- Maintain hive temperature between 32 °C and 35 °C during treatment to facilitate volatilization of active compounds.
- Provide adequate ventilation to prevent ethanol buildup.
Efficacy assessment
- Collect a sample of approximately 300 adult bees 14 days after the final application.
- Perform a sugar‑shake test: place bees in a jar with powdered sugar, shake, and count dislodged mites under a microscope.
- A reduction of mite count by at least 80 % indicates successful control.
Safety and residue
- Thujone levels in honey may rise slightly; conduct residue analysis if honey is intended for market.
- Avoid treating colonies during peak nectar flow to reduce contamination risk.
Integration with other controls
- Pair tansy treatment with mechanical methods such as drone brood removal to enhance overall mite management.
- Rotate with different organic acids (oxalic, formic) in subsequent seasons to prevent resistance development.
Following this structured regimen delivers consistent acaricidal results while preserving colony health and minimizing chemical residues.