How and with what should bees be treated for mites? - briefly
Bees are commonly treated for varroa mites using organic acids (oxalic acid vaporized or sugar‑shocked, formic acid strips) and synthetic miticides (e.g., fluvalinate, amitraz) applied according to calibrated dosage schedules. Effective control also relies on regular mite counts, brood interruption techniques, and breeding for hygienic or resistant colonies.
How and with what should bees be treated for mites? - in detail
Effective control of bee parasites requires accurate identification, regular monitoring, and a combination of chemical, biological, and mechanical methods.
Monitoring involves counting mites on a sample of adult workers or brood using a sticky board, sugar roll, or alcohol wash. Thresholds vary by region, but a common rule is to treat when more than three mites per 100 bees are detected.
Chemical options include synthetic acaricides such as fluvalinate, coumaphos, and amitraz. These substances must be applied according to label rates, typically as a strip placed in the hive for a defined period (e.g., 6‑8 weeks for fluvalinate strips). Rotation of active ingredients is essential to prevent resistance. Organic treatments comprise formic acid, oxalic acid, and thymol. Formic acid is applied as a gel or pad, effective against mites in brood and adult bees; exposure time ranges from 8 to 12 days, depending on temperature. Oxalic acid is administered by vaporization or sugar syrup drench, targeting adult mites; a single treatment in late autumn is common. Thymol, used as a board or strip, works best at 20‑30 °C and requires a 2‑week exposure.
Biological control uses the predatory mite Stratiolaelaps scimitus (formerly Hypoaspis miles) introduced into the hive. These predators consume varroa larvae and can reduce mite populations when applied in multiple rounds.
Mechanical methods include brood interruption, where the queen is confined to lay in a queenless frame for several days, forcing the colony to raise a new brood cycle without sealed cells, thereby breaking the mite reproductive cycle. Drone brood removal exploits the mite’s preference for drone cells; heavily infested drone frames are taken out and frozen before disposal.
Integrated pest management (IPM) combines the above tactics: start with monitoring, apply a chemical or organic treatment when thresholds are exceeded, follow with a brood interruption or drone brood removal, and conclude with a biological or mechanical step. Record-keeping of treatment dates, products used, and mite counts enables evaluation of efficacy and adjustment of future protocols.
Key considerations:
- Use the lowest effective dose to minimize residue buildup.
- Avoid consecutive applications of the same chemical class.
- Maintain hive temperature within the optimal range for each treatment.
- Ensure bees have adequate food stores before applying any medication.
- Dispose of used strips, boards, and contaminated equipment according to safety guidelines.