DIAGNOSIS OF Nosema apis INFECTION BY INVESTIGATIONS OF TWO KINDS OF SAMPLES: DEAD BEES AND LIVE BEES

All the techniques of diagnosis of Nosema apis infection, recommended in the OIE (World Organisation for Animal Health) Manual of Diagnostic Tests and Vaccines for Terrestrial Animals 2004, are based on the investigation of samples of live bees collected at the entrance of the hive. However, sometimes, it is impossible to get such samples for instance when the colony has died. On the other hand, it would often be useful for beekeepers to know the health status of the colonies in early spring. At this time obtaining samples of live bees at the hive entrance is very difficult in many areas. In this work the method of investigation of the dead bees collected from the bottom board of the hive just before the time of the first spring flight, or from the dead colony, is described. In many countries with a climate similar to or cooler than in Poland such samples are easy to get. The method consists of the grinding of 100 whole bees in 50 ml of water, passing the suspension through a filter made of about 25 GSM (g/m2) Nonwoven PP (polypropylene) cloth, and microscopic examination of the filtrate, under bright-field. The comparison of the method in relation to the simple nonquantitative method of investigation of live bees, from the OIE Terrestrial Manual, was performed.