Different broadspectrum external pathogen and non-pathogen effects from environment or used in controlling varroa mites could have drastic eff ects on bee colonies. Sublethal eff ects can lead to physiological modifi cations and changes in bee behavior and cellular physiology consistent with chemically induced stress responses. Research focuses on damage that can be repaired, cells that remain viable after intermediate level of damage, and cells that undergo apoptosis or necrosis after a high level of damage primarily to brain and gut. Cellular biomarkers have been developed to evaluate chronic exposure of bees to pesticides to understand the eff ects of synergistic action of xenobiotics in the environment and to separate the eff ects of pathogens and pesticides. These studies can bring substantial benefi ts to ag ro- ecosystems.
COBISS.SI-ID: 3726184
The aim of this study was to improve and standardize cage systems for maintaining adult honey bees under in vitro laboratory conditions. We experimentally evaluated the impact of different cages, on the physiology and survival of honey bees. Several experiments of the acaricides efficacy are conducted 'in vitro' on caged bees. We identified three cages that provided a satisfactory environment for supporting bee survival. We determined that a leaking-and- dripping-proof feeder was an integral part of an effective cage system and a feeder modified from a 20 ml plastic syringe displayed the best result in providing steady food supply to bees.
COBISS.SI-ID: 4410984
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
This is the first study that showed that pesticides could affect food transfer between workers of honeybee. We investigated whether coumaphos, an organophosphate used to control the parasitic mite Varroa destructor, affects trophallaxis in honeybees. Donors were treated with coumaphos one hour before experiments. In this, uncontaminated food was transferred from donors to recipients. The amount of food transferred was measured (a) directly by weighing food or (b) indirectly by the number of recipients that died due to insufficient trophallaxis. A large reduction in the amount of transferred food was observed when donors received 5 μg of coumaphos. High mortality was observed among the recipients that were fed by donors treated with 2 or 5 μg of coumaphos indicating insufficient food transfer. Demonstrated side effects of coumaphos on trophallaxis could reduce distribution of this systemic agent in the colony and decreases its efficacy.
COBISS.SI-ID: 2500175