Comparison between the usefulness of preparations: Acid Pla Tan Liquid and Efektywne Mikroorganizmy in the control of Nosema spp. infection in bees

摘要

Bearing in mind that there is no effective medication to control nosemosis, the authors assessed the usefulness of Acid Pla Tan Liquid [AP] and Efektywne Mikroorganizmy [EM] in the management of this disease in bees. Prior to field tests, we carried out laboratory examinations for the toxicity of the preparations in cages with bees, and then on colonies infected with Nosema spp. The evaluation of the effectiveness of the preparations was carried out on 36 colonies infected with nosemosis. In bees administered syrup containing the tested preparations at concentrations: 2 ml, 1 ml, 0.5 ml, 0.25 ml, and 0.125 ml per 1 l, we did not observe abnormal behaviors or workers' deaths. Bees in complete colonies with therapeutic syrup containing AP administered 3 times at a dose of 1 ml/1 l, and with EM at a dose of 2 ml/1 l behaved similarly. Worker bees from these colonies left the hive in a usual manner to fly for forage, brought pollen, found their way back home accurately, young bees emerged from their cells, the queen laid eggs, and young bees raised brood. After 15 days from the completion of the treatment, we found out that AP eliminated Nosema spp. infection at 100.0%, and EM at 42.9%. The autumn control triple administration of AP at a dose of 1 ml/1 l, and EM at a dose of 2 ml/1 l, to colonies with different intensity of Nosema spp. infection proves a higher effectiveness of AP (75%) than EM (58.3%). A mean of a significantly lower number of spores was observed in colonies from group AP as compared both to the control group and group EM, in which the number of spores was nevertheless significantly lower than in the control group.