Differential Effects of Eucalyptus, Garlic, Rosemary, and Basil Smokes on Varroa destructor Mite Fall and Apis mellifera Colony Calmness
Abstract:
Varroa destructor continues to cause major winter losses in Apis mellifera apiaries across Iraq, while repeated use of synthetic acaricides has led to resistance and residue concerns. Plant-based smoke may provide a low-cost alternative, but beekeepers need a practical delivery method. We tested four botanical smokes using compressed cardboard egg cartons—a common smoker fuel in local apiaries—as a substrate to extend burn time. Garlic smoke gave the highest might fall at 95.6% efficacy, whereas eucalyptus smoke produced the calmest colonies at 4.5/5.0. This indicates treatment choice can be matched to the beekeeper’s immediate need.
Methods: We worked with 36 equal-strength colonies in babylon from March–May 2025. Groups received 30-second smoke applications of Eucalyptus camaldulensis, Allium sativum, Rosmarinus officinalis, or Ocimum basilicum mixed with egg carton, plus egg carton-only and untreated controls. Mite fall was counted on sticky boards after 48 h. Calmness was scored 0–5 by the same observer during inspection. Data were compared using One-Way ANOVA and Duncan’s test, P ≤ 0.05.
Results: Garlic smoke produced 3.83 ± 0.19 mites/colony/48h, significantly more than all other treatments. Eucalyptus smoke gave the highest calmness score at 4.50 ± 0.22. Rosemary and basil showed intermediate effects. Egg carton alone had minimal impact.
Conclusion: Garlic smoke is suited for targeted Varroa knockdown when mite counts are high, and eucalyptus smoke for routine inspections where beekeeper safety matters. Using egg carton as a carrier makes the method affordable and easy to adopt in organic IPM programs.
KeyWords:
Varroa destructor; Apis mellifera; Botanical smoke; Eucalyptol; Allicin; Organic beekeeping; IPM; Egg carton substrate
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