What are phoretic mites and where are they found on bees? Key Signs & Control Tips

Phoretic mites, specifically Varroa mites, are ectoparasites that attach themselves to honey bees, primarily residing on the abdomen. They are most commonly found tucked between the abdominal sclerites of worker or drone bees, where they latch on to feed on hemolymph (bee blood). Their presence signals a more advanced infestation stage (Stage 2-5), indicating significant colony stress and potential health decline. These mites are a critical concern for beekeepers as they weaken bees, transmit viruses, and contribute to colony collapse if left unmanaged.

Key Points Explained:

1. Definition of Phoretic Mites

   • Phoretic mites refer to Varroa mites (Varroa destructor) in their dispersal phase, where they hitchhike on adult bees to spread within or between colonies.
   • Unlike reproductive mites (found in brood cells), phoretic mites are mobile and feed on adult bees, making them easier to detect during inspections.

2. Typical Location on Bees

   • They predominantly attach to the abdomen, specifically:
     • Underneath the bee, nestled between the abdominal sclerites (hardened plate-like segments).
     • This positioning shields them from grooming efforts by bees and allows steady access to hemolymph.
   • While workers and drones both host phoretic mites, drones are more vulnerable due to their longer developmental period and larger size.

3. Implications of Phoretic Mite Presence

   • Infestation Severity: Their appearance on worker bees suggests the colony has reached Stage 2-5 of mite damage, where:
     • Mite populations are high enough to spread beyond brood cells.
     • Bees exhibit weakened immunity, shorter lifespans, and increased viral loads (e.g., deformed wing virus).
   • Colony Health: Left unchecked, phoretic mites contribute to:
     • Reduced foraging efficiency.
     • Higher winter mortality rates.
     • Potential colony collapse.

4. Monitoring and Management

   • Detection Methods:
     • Alcohol washes or powdered sugar rolls to dislodge mites from bees.
     • Visual inspections of abdominal folds (especially in drone congregations).
   • Intervention Strategies:
     • Chemical Treatments: Miticides like formic acid or oxalic acid during low-brood periods.
     • Mechanical Controls: Drone brood removal, as mites prefer drone cells for reproduction.
     • Integrated Pest Management (IPM): Combining monitoring, resistant bee breeds, and targeted treatments.

5. Why This Matters for Beekeepers

   • Phoretic mites are a leading indicator of colony health. Early detection and intervention can prevent irreversible damage.
   • Understanding their behavior (e.g., preference for abdominal attachment) informs more effective treatment timing and methods.

By recognizing phoretic mites’ hiding spots and their role in infestation progression, beekeepers can take proactive steps to safeguard colonies—ensuring the sustainability of both bees and the ecosystems they support.

Summary Table:

Protect your apiary from phoretic mites—contact HONESTBEE for expert-recommended beekeeping supplies and wholesale solutions!