Crithidia mellificae was readily detected throughout the timecourse. In contrast to most other prevalent microbes and viruses, relative Crithidia levels peaked in the winter (January 2010). The effects of C. mellificae on the honey bee host remain relatively uncharacterized compared to those of C. bombi on bumble bee, which include reduced worker fitness and colony survival [66, 99] . To date, there are only a few reports of C. mellificae infection of honey bees in the literature including early work describing the first isolation and culture of this organism in 1967 from Australian honey bees [67] . This work tested the effect of feeding C. mellificae to honey bees and demonstrated similar mortality rates in infected and uninfected bees [67] . More recently, similar trypanosomatid prevalence and loads were reported in CCD-affected colonies and healthy controls [9, 10] . Although current data suggest that C. mellificae does not dramatically affect colony health additional pathogenesis research in honey bees is warranted considering the detrimental effects of C. bombi on bumble bee colonies.