Samples (,50-100 bees) were collected into 50 mL Falcon tubes using a modified hand-held vacuum cleaner from both the entrance and interior of the hive and immediately put on dry ice for overnight shipment to our laboratory. Samples were stored at 280uC until RNA extraction; excess bees were archived for longterm 280uC storage. Time-course samples were collected monthly from April 15 (week 1) through July 14 (week 14), 2009 and weekly samples were attempted thereafter, however due to inclement weather or shipping logistics the samples for weeks 15, [28] [29] [30] 32 , and 39-41 were not collected. A total of 864 samples were obtained and 431 exterior samples were analyzed.