Permanent prevalence of Nosema ceranae in honey bees (Apis mellifera) in Hungary.

Nosema ceranae is present in honey bee (Apis mellifera L.) colonies worldwide. Studies on the comparative virulence of N. ceranae and N. apis showed significant differences in individual mortality, and the prevalence of N. ceranae seems to be predominant in both the continental and the Mediterranean climate regions. This study attempted to monitor the geographical and seasonal distribution of these two Nosema species in Hungary, using a simple laboratory method. The distribution of N. ceranae and N. apis infection rates along all seasons was homogeneous (P = 0.57). In co-infected samples, the intensity of N. ceranae infection was always significantly higher than that of N. apis infection (P < 0.001). The infection rate of infected bees in exterior samples was higher than in interior samples in each season; however, the differences were not statistically significant. The species N. ceranae had been present in Hungary already in 2004. Statistical analysis of data shows that the infection level is best represented by sampling exterior bees to establish the proportion of infected bees rather than by determining the mean spore count.

Evaluation of cage designs and feeding regimes for honey bee (Hymenoptera: Apidae) laboratory experiments.

The aim of this study was to improve cage systems for maintaining adult honey bee (Apis mellifera L.) workers under in vitro laboratory conditions. To achieve this goal, we experimentally evaluated the impact of different cages, developed by scientists of the international research network COLOSS (Prevention of honey bee COlony LOSSes), on the physiology and survival of honey bees. We identified three cages that promoted good survival of honey bees. The bees from cages that exhibited greater survival had relatively lower titers of deformed wing virus, suggesting that deformed wing virus is a significant marker reflecting stress level and health status of the host. We also determined that a leak- and drip-proof feeder was an integral part of a cage system and a feeder modified from a 20-ml plastic syringe displayed the best result in providing steady food supply to bees. Finally, we also demonstrated that the addition of protein to the bees' diet could significantly increase the level ofvitellogenin gene expression and improve bees' survival. This international collaborative study represents a critical step toward improvement of cage designs and feeding regimes for honey bee laboratory experiments.