We studied the acute toxicity in honeybee colonies exposed to acaricide coumaphos treatment. Two coumaphos strips were inserted each colony and few hours after the treatment un-normal honey bee worker behavior was observed. Bees left hives, fly extensively around them, cluster on the front hive wall, and drop down in the grass in front of the hives. Workers were also dying around the treated hives with extended wings, and curved, shortened and tremoring abdomens. Acaricide dose given to the National Standard hives in these conditions can induce acute toxic effects in individual bees and consequently reduce colony populations. Acaricide treatment in closely placed bee hives with strong colonies should therefore be performed with great caution.
COBISS.SI-ID: 3771752
Experiments were conducted to assess the comparative effi cacy of: Thymovar (Andermatt BioVet AG); Apiguard (Vita Europe Ltd., UK); an oxalic acid solution (OA) which consisted of 2.9% oxalic acid and 31.9% sugar in water; and amitraz fumigation, for controlling the honey bee mite Varroa destructor. Mite mortality increased significantly (p(0.001) in the Thymovar, Apiguard, OA or amitraz treated colonies. The relative mite mortality after: four OA applications, two Thymovar or two Apiguard applications during August and September in the Senično apiary was 41.80% (±14.31), 14.35% (±10.71), and 18.93% (±13.56), respectively. Two Apiguard applications and a single amitraz treatment resulted in reducing the mite populations by 19.71% (±12.61) and 23.89% (±14.25), respectively. At the Mediterranean located apiary of Vipava, the Thymovar and Apiguard treatments trigged 59.02% (±17.28) and 46.50% (±13.33) of the total mite reduction. The results indicate that OA, Thymovar, Apiguard or amitraz fumigations are of limited use during the brood periods.
COBISS.SI-ID: 4002408