You will notice that other bee diseases are considered
Here's some data that Randy Oliver has on his web site:
Results
http://www.scientificbeekeeping.com/index.php?option=com_content&task=view&id=67
Mean survival of colonies (arbitrarily set at 4 frames or stronger) at April 3 was 50%. Highest survival (88%) was in the pollen substitute/fumagillin group; lowest survivals were in the untreated controls (38%) and in the bleach treatment (25%). The data of this trial are shown in the Appendix.
The colonies showing the least amount of strength loss from December 15 to February 25 were the group fed pollen substitute plus fumagillin. By April 3, mean colony strength had generally rebounded to approximately their starting strength for most groups. The notable exceptions were the pollen substitute/fumagillin group, whose mean strength increased by 227%, and the bleach group, which had only recovered 64% of their original strength.
On the average, 3 colonies in each group of 8 were over 8 frames on April 8. Only two groups were marginally better (to 4 colonies out of 8)—the pollen substitute/fumagillin and HoneyBHealthy. However, two of the HoneyBHealthy colonies had started at 10 frames, so I don’t feel that HoneyBHealthy’s performance in this regard was notable.
Dr. Nancy Ostiguy generously volunteered to have a student perform nosema spore counts of the bee samples. Unfortunately, they were not complete by the time of this progress report.
The great variability of colony performance likely precludes any statistical significance, but I will run statistics when the spore counts are completed.
In April, I spot-checked a large proportion of the surviving colonies for nosema levels. The majority were still infected in the range of a few million spores per bee. I only found one colony that had few spores. Despite this infection, most of the colonies that survived the winter went on to produce honey, and in several cases, to produce swarms. The bees in the swarms that I captured all ran at infection levels of a few million spores per bee.
However, not all colonies built up. Several colonies continued to dwindle, or stayed stuck at about 4 frames for most of the season. I could not find any correlation between colony strength and buildup and nosema levels. The one observation that stood out was that those colonies that did not build up generally had spotty brood, and sick larvae and pupae. The symptoms were generally EFB-like, or sacbrood-like, but it isn’t clear that those diseases were actually the cause.
I sent samples of sick bees to Dr. Jay Evans at USDA, Dr. Nancy Ostiguy at Penn State, Dr. Michelle Flenniken at U.C. Davis, and Dr. Jerry Bromenshenk/Dave Wicks at BVS. The three report results back to date are shown below.
Results from Dr. Jay Evans
Sample 1 Sacbrood virus, possible N. apis
Sample 2 none
Sample 3 ABPV, BQCV, EFB
Sample 4 low sacbrood, low AFB
Sample 5 low sacbrood, EFB, Nos. ceranae
Sample 6 BQCV, Nos. ceran
Sample 7 BQCV, DWV, IAPV, Nos. ceranae
Regards,
Ernie