Thank you for your reply Walter.

There are three parts to my response. (1) Previous testing. My posts with respect to test results for DWV are part of my interrogation of the 2010 testing as well as more recent testing for the 2016 Canadian National Honey Bee Health Survey.  However, prior to 2010 there isn’t much to question because the testing was so limited in terms of the pathogens tested for. 

Prior to the Shutler team's testing in 2010 (Shutler, et al., 2014), the domestic stock of honey bees in Newfoundland and Labrador was surveyed for only a tiny number of pathogens, in 2004, 2007, and 2009 (Williams, et al., 2010:585). Informal surveys by Dick Rogers in 2004 detected AFB, Chalkbrood and EFB but not trachael mite or Varroa destructor (Williams, et al., 2010:585). Nosema apis was detected for the first time in 2007 (Williams, 2010:3).  Additional testing in 2009 confirmed the presence of Nosema apis in the NL honey bee stock and the absence of trachael and Varroa mites (Williams, et al., 2010:586).  The 2010 survey by Shutler's team was the first to provide a more comprehensive baseline of pathogens (e.g. viruses), diseases and pests in the NL honey bee stock.

(2) Screening of imported packages. As for the 130 packages imported from Western Australia in April 2016, the test results are available here. http://nlbeekeeping.ca/data/documents/Response-to-NLBKA-Re-Nosema-ceranae-_-July-4-2017.pdf They were tested on the basis of sampling by the provincial apiarist and testing at the National Bee Diagnostic Centre at Beaverlodge.  Total sample size is unknown, although it’s described as a “rolling sample.”  Results were made available to our beekeeping association in September 2016 and reported at our November AGM that year. See discussion of quarantine below.   

Of course, screening of honey bee imports to Canada is handled exclusively by the Canadian Food Inspection Agency (CFIA) informed by the risk assessment methods/protocols of the World Organisation for Animal Health (OIE, see sections dealing with honey bees in the Terrestrial Animal Health Code and the OIE’s Manual of Diagnostic Tests and Vaccines for Terrestrial Animals).  If you go through the CFIA’s Automated Import Reference System on-line you will see that the pests and diseases screened re. imports from Australia are Varroa destructor, Tropilaelaps spp., SHB, Apis cerana, AFB, and EFB. They also screen for Africanized genetics. The screening process at the border is pretty much a paper-work exercise, based on an examination of the CFIA Import Permit and the Zoosanitary Export Certificate from the exporting country. A CFIA vet will do a walk-about, visual inspection of a pallet of packages for SHB at the port of entry (“Inspection Port”), but if nothing is seen, and the paper work is in order, the shipment is accepted.  The OIE recommended pests and diseases for international screening are AFB, EFB, tracheal mite, Tropilaelaps spp., Varroa spp., and SHB.  So, you can see that an importing country can add or subtract to the OIE list based on its own science-based risk assessments.  I note furthermore that “In addition to the requirements of the CFIA, the importer must also comply with any additional requirements imposed by the Canadian province of final destination and any other Canadian province that the honeybees transit through en route to their final destination. The provincial apiarist(s) must be contacted prior to importation to obtain the current requirements” (re. imports to Canada from Australia).  In Newfoundland and Labrador, our import regs. under the Animal Health and Protection Act target tracheal mite, Varroa destructor, greater wax moth, and SHB.  I do not know how our provincial regulations get translated into international importation requirements established by the CFIA. Although the Canadian Association of Professional Apiculturists (whose members include provincial apiarists) communicates risk assessments and recommendations re. importation to the CFIA, communications between our province and the CFIA are opaque. E.g., our 2016 importation from Western Australia did not screen for the greater wax moth even though it's listed in our regs. (although it’s hard to imagine how wax moths could end up in a package – there’s no comb).

(3) Possibility of contamination and quarantine.  Our Animal Health Regulations (Animal Health and Protection Act) state that “upon entry into the province all honeybees and honeybee hives…shall be quarantined on the premises of the importer for a period of 12 months from the date of entry….Honeybees and honeybee hives shall not be moved from the premises of the importer during the period of quarantine…”  As I know it, 100 of the packages were quarantined at an undisclosed location in central Newfoundland. This would have been an effective quarantine location given its isolation from other apiaries, assuming that this importer kept the packages well away from his domestic stock, that was probably including in the 2016 National Honey Bee Health Survey.  However, 30 of the packages were brought to the northeast Avalon which is not an effective quarantine location because this part of the Island is one giant apiary given overlapping honey bee flight zones, drone congregation areas,  swarming, etc.  

We know that five commercial operators were sampled for the 2016 National Honey Bee Health Survey, although their identities are confidential.  Nonetheless, I’d say that one of the five is on the NE Avalon;  someone with one or more apiaries within bee flight distance of the WA packages.  Therefore, I guess there was a possibility of contamination both ways between the WA packages and the pre-existing domestic stock.  However, WA is also free of Varroa destructor, so viruses associated with this pest or amplified by it would not be a factor.  In other words, it cannot be a question of mutating DWV brought in with bees from a stock that has Varroa because WA is Varroa-naïve like us. Interestingly, one of the WA samples was positive for DWV, while all of the domestic samples were negative.

In conclusion, contamination is a possibility I guess, but in the absence of data/evidence it’s difficult to attribute differences in test results to this variable, particularly with respect to apiaries geographically remote from the quarantined WA apiaries.  In any event, the quarantine is now over, and the provincial government considers these bees to be part of the domestic stock.  We retain all of this information “on file” and take it into consideration when trying to make sense of our test results.

References

Shutler, Dave, Krista Head, Karen L. Burgher-MacLellan, Megan J. Colwell, Abby L. Levitt, Nancy Ostiguy, Geoffrey R. Williams. 2014. “Honey Bee Apis mellifera Parasites in the Absence of Nosema ceranae Fungi and Varroa destructor Mites.” PLOS One. 9(6): E98599. Doi:10.1371/journal.pone.0098599.  

Williams, Geoffrey R. 2010. 2009 Newfoundland and Labrador Honey Bee Disease Survey. Report to Forestry and Agrifoods Agency, Government of Newfoundland and Labrador. February.

Williams, Geoffrey R., Krista Head, Karen L. Burgher-MacLellan, Richard E.L. Rogers, and Dave Shutler. 2010. “Parasitic Mites and Microsporidians in Managed Western Honey Bee Colonies in Newfoundland and Labrador, Canada.” Can. Entomol. 142:584-588.

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