Seasonality of specific pathogens in our time-course study representing 2,155 individual bees from 431 samples varied, although many including BQCV, APBV, SBV, Nosema, exhibited reduced June and peak August levels. Peak incidences of these organisms in the spring and late summer are likely attributable to increased brood rearing [19, 78, 87] and foraging during these seasons [88] . Increased brood rearing during the summer, results in a greater number of bees capable of transmitting pathogens to other members of the colony living in very close proximity [19] . Honey bee viruses are transmitted vertically via infected queens and horizontally via the oral-fecal route or through the exoskeleton [19, 21] . Foraging activity also increases pathogen exposure [88] and may also stress the bees so that inapparent infections reach detectable levels. Although other sources of stress, such as transportation and poor nutrition, are hypothesized to increase pathogen levels [10] , these factors were minimal during the summer when the monitor colonies were stably situated in South Dakota foraging on diverse pollen and nectar sources, including alfalfa (Medicago sativa L.), sweet clover (Melilotus spp.) and a variety of other flowering plants in June with increasing availability of corn (Zea mays ssp.) and soybean (Glycine max) pollen later in the summer. Notably, these colonies were part of a typically managed commercial beekeeping operation and therefore received nutritional supplements, protein paddies and sugar syrup throughout the year (Materials and Methods). Adequate monitor colony nutrition may have played an important role in the rapid virus clearance observed in our study. Although further experimental validation is needed, recent work examining the effects of nutrition on DWV titer in caged-bee studies demonstrated that viral titer was reduced by pollen and protein supplementation [89] . In addition, anti-mite and antimicrobial treatments in the spring and late-fall may have accounted for the lower pathogen levels at those times of year and in turn for the relatively high levels during the summer (Materials and Methods). We did not observe either increased incidence or abundance of any of the microbes and viruses monitored in our study after long distance transport.