Paper prepared by  Karen  Rennich, Jeff Pettis, Dennis S Vanengelsdorp, Jerry Hayes, Michael Andre, Rob Snyder, Karen Roccasessa, Nathan Rice, Jay Evans, Dawn Lopez, Vic Levi, Margaret Smith Nishit Patel and Robyn Rose

Executive summary

The 2010 Limited National survey, focusing on 13 states, was performed to expand and augment the baseline pest and pathogen data collected from the pilot study conducted in 2009.It is the most comprehensive U.S. honey bee pest and disease survey to date.  The primary focus of this survey was to verify the absence of the parasitic mite Tropilaelaps and other exotic threats to the U.S. bee population (e.g., Apis cerana). Under current international trade agreements, the U.S. cannot deny import permits from other nations unless the exporting nation has a disease, parasite, or pest of honey bees that is not found in the U.S. Establishing the absence of threats to honey bee populations not thought to be present in the U.S. was the primary objective of this effort.

To capitalize on the information gathered from this survey, samples were analyzed for other honey bee diseases and parasites known to be present in the U.S. The survey results are used to gauge the overall health of colonies and to help create a disease level baseline to help interpret ongoing and future epidemiological studies.  The 2010-2011 National Survey effort was limited to collection of samples from 13 states including Alabama, California, Florida, Georgia, Hawaii, Indiana, Michigan, New York, Pennsylvania, South Dakota, Tennessee, Texas and Washington.  A total of 349 samples representing over 2,700 colonies were collected.  A further expansion of this survey is planned for 2011/2012 with the number of participating states increasing to 33.

The survey samples were analyzed for 11 known honey bee viruses, pests and pathogens including a DNA test for any occurrence of Apis cerana, the Asian honey bee. Molecular primers and a restriction enzyme test diagnostic for mitochondrial DNA of A. cerana were created for this survey and a broad sample representing all states was tested without a single detection.  Slow Paralysis Virus (SPV), the only virus included in this year’s testing that is not currently found in the U.S., was examined in all samples and no detection was made.  No diseases or parasites of bees not already known to exist in the country were discovered. Only one virus, Deformed Wing Virus (DWV), was found in all 13 states.  Also common to all states were the parasitic microsporidian Nosema ceranae, and the trypanosome Crithidia. It is not known at this time if Crithidia negatively or positively affect colony health.   As in the pilot study of 2009-2010, N. ceranae was identified in all samples positive for Nosema spp. while Nosema apis were not found in any state.  For the second year, we saw no evidence of Tropilaelaps mites, nor honey bee tracheal mites (Acarapis woodi) in any sample. Honey bee tracheal mites are known to exist in the country and our failure to find them may be the result of our sampling procedure.  Honey bee tracheal mites are most abundant in overwintering colonies and all samples were taken from colonies actively rearing brood.  Varroa mites continued to be observed in all states with the exception of the Hawaiian Islands of Maui, Kauai and Molokai.

This survey was designed to be representative of the managed honey bees across the broad geography of the United States.  We chose states as the units to determine the distribution of samples taken as funds were insufficient to allow for a more comprehensive representation based on colony abundance.  We targeted key beekeeping states as a primary selection criterion and then secondarily, we chose states to fill in geographic voids to insure a degree of coverage across the U.S.  When choosing states, attempts were made to include a distribution of states that represented queen production, honey production and had stationary and migratory practices. We also focused on high risk states that have key ports, long growing seasons and diverse agricultural crops.  The results can thus be interpreted as representative of the pests and pathogens present in the U.S.


This 13 state USDA survey of honey bee pests and pathogens began in 2010 and was completed in 2011.  The survey encompasses all states sampled in the 2009/2010 pilot study plus 10 additional states.  Funding was provided by the USDA Animal and Plant Health Inspection Service (APHIS) and the survey was conducted in collaboration with the USDA Agricultural Research Service (ARS), Pennsylvania State University (PSU) and the Florida Department of Agriculture and Consumer Services (FDACS).  A total of 349 samples were collected from 50 apiaries in California (17 from migratory beekeepers who were in that state for pollination contracts and 33 from beekeepers originating from there), 24 from Hawaii and 25 from the remaining states (Alabama, California, Florida, Georgia, Hawaii, Indiana, Michigan, New York, Pennsylvania, South Dakota, Tennessee, Texas and Washington).

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Last Updated (Friday, 26 August 2016 16:27)