Screening Swedish bees for pahogens shines new light on the parasite Gregarine

Sammanfattning: are under pressure from habitat loss, environmental stress and pathogens including viruses. Research have shown viral infections to be one of the major causes of colony losses. The purpose of this study was to screen three viruses; Deformed wing virus, Slow bee paralysis virus and Acute bee paralysis virus but also three parasites; Nosema spp., Crithidia spp., and Gregarine spp. due to their mortality and the lack of knowledge regarding some of the pathogens’ habitat and hosts. During the years of 2015 and 2016 three bee species were collected in a number of 156 samples including honeybees, bumblebees and solitary bees equally divided. Extraction of RNA and DNA was done using only the abdomen which was homogenised by the use of MixerMill and later extracted on a QIAcube. Real-time qPCR was used in this study as a qualitative screening method. DWV was detected primarily in honeybees, infecting as much as 70 %. The parasite known to have bumblebees as its host, namely Crithidia spp. was detected in 23 % of the honeybees collected, 15 % of the bumblebees and 2 % of the solitary bees. According to the results; Crithidia spp. is no longer a specific parasite found in bumblebees but have broaden its host spectrum to both honeybees and solitary bees. Furthermore, the parasite detected in most samples was Gregarine spp. and was detected in 50 % out of the bees collected suggesting that this parasite is common in Swedish bees.