Apicystis bombi, a protozoan parasite of bumblebees, acts as an emergent infectious disease

MAHARRAMOV, J.; MEEUS, I.; MAEBE, K.; ARBETMAN, M.; MORALES, C.; GRAYSTOCK, P.; HUGHES, W. O. H.; PLISCHUK, S.; LANGE, C. E.; DE GRAAF, D. C.; ZAPATA, N.; PEREZ DE LA ROSA, J. J.; MURRAY, T. E.; BROWN, M.; SMAGGHE, G.

Pittsburgh, Pennsylvania

Encuentro; 46th Annual Meeting of the Society for Invertebrate Pathology Conference on Invertebrate Pathology and Microbial Control; 2013

Society for Invertebrate Pathology

The only native bumblebee, Bombus dahlbomii, is disappearing in the temperate forests of south Argentina and Chile. It has been hypothesized that Apicystis bombi, a neogregarine parasite, has recently spilled over from introduced bees and is facilitating current losses of native B. dahlbomii. Indeed if this parasite is introduced in novel host populations it could lead toward emergent diseases and epidemics resulting in rapid decline of B. dahlbomii. Until now it was impossible to molecularly characterize A. bombi haplotypes. Therefore it was difficult to prove that A. bombi, recently identified in Argentina, was introduced or already present before introduction of non-native pollinators like the European honeybee (Apis mellifera), and the two bumblebees Bombus ruderatus and Bombus terrestris. By use of molecular markers, the internal transcribed spacer 1 and 2, we studied within species genetic variability to identify the origin of A. bombi in Argentina. Only one cluster of A. bombi haplotypes was found in Argentina, with its most abundant haplotype identical to the most abundant one in Europe, and with a minimal structuring between Argentina and Europe (only 15.2 % of the genetic variation is explained by location). Although our data does not tell anything about the direction(s) of transmission it proves that for A. bombi no geographical separation is present and A. bombi is acting as an emergent infectious disease. Furthermore, we show a random transmission of A. bombi between the honeybee and the two Bombus species, proving this parasite lives in a multiple-host network.