Pathogens, parasites, and parasitoids associated with bumble bees (Bombus spp.) from Uruguay

As elsewhere in the world, bumble bees play a vital role as pollinators in Uruguay, but knowledge on their health status is still limited. Between September 2012 and May 2013, 403 adult individuals of the two species of Bombus known for the country (Bombus atratus, Bombus bellicosus) were collected in six localities. We found that 177 (119 B. atratus, 58 B. bellicosus) were harboring one or two types of pathogens, parasites, or parasitoids. Identification of these natural enemies carried out by morphological or molecular procedures revealed the presence of two species of Microsporidia [Nosema ceranae (prevalence: 18.2 % in B. atratus; 44.9 % in B. bellicosus), Tubulinosema pampeana (prevalence: 13 % in B. atratus)], two species of Nematoda [Sphaerularia bombi (prevalence: 40.4 % in B. atratus; 40 % in B. bellicosus) and an unidentified Mermithidae (prevalence: 0.8 % in B. bellicosus)], and one species of Diptera parasitoid (prevalence: 3.2 % in B. atratus; 4.2 % in B. bellicosus). Except N. ceranae, none of the other species have been previously reported in Uruguay.