01864nas a2200217   4500000000100000000000100001008004100002260007000043653001400113653001500127653001400142653001600156100001500172700001300187700001500200700001500215245008000230490000800310520131400318022001401632       2018                            d  c11/2018bSchlütersche Verlagsgesellschaft mbH & Co. KGaHannover10ahoney bee10aNosema spp10anosemosis10adiagnostics1 aL Horchler1 aS Gisder1 aO Boecking1 aE Genersch00aDiagnostic value of faecal spots on and in honey bee (Apis mellifera) hives0 v1313 aNosema spp. infections are widely distributed in populations of the European  honey bee. Most of these infections are covert; hence, infected individuals and colonies do not show obvious clinical symptoms. Sometimes, overt outbreaks of infections of adult bees with Nosema spp. (nosemosis) occur and those are typically characterized by the clinical symptom ‘diarrhoea’. Hence, colonies suffering from nosemosis can be recognized by faecal spots visible at the hive entrance, on frames, and on combs. Whether only Nosema ( N.) apis or also N. ceranae causes dysentery is still controversially discussed, as is the possibility to identify a nosemosis outbreak just based on faecal spots. Therefore, the goal of our study was to evaluate the value of faecal spots for the diagnosis of nosemosis by microscopic and molecular analyses of faecal spots and worker bees collected from the respective colonies. We show that overt outbreaks of N. ceranae infections are not that different from outbreaks of N. apis infections: Both are associated with diarrhoea resulting in faecal spots at the hive entrance and inside the hive. However, not all colonies exhibiting faecal spots were suffering from nosemosis suggesting that the mere presence of faecal spots is not sufficiently reliable for diagnosing nosemosis.  a0005-9366