This week’s
blog brings you the final update on our regions 2020 wild blueberry crop. Wild blueberry producers in New Brunswick had
some challenges this season. The NB provincial
wild blueberry expert has supplied a report with all the details which you can
read below.
The limited
chemical miticide options for beekeepers are a concern. We are seeing very good efficacy with Apivar®
(active ingredient: Amitraz; chemical group: Formamidine) but the worry is that
mites may develop widespread resistance.
New and exciting research, being done by a team from Alberta, is working
to find alternative drug treatments for Varroa control.
New Brunswick 2020 Wild Blueberry Crop Update
New Brunswick
wild blueberry growers harvested an estimated 28 to 29 M lbs, compared to the
2019 crop of 67.3 M lbs and the 2018 crop of 53.5 M lbs, when similar fields
were harvested. An estimated 16,500 acres were harvested in 2020. The decrease in total production is due
partially to a frost in the spring and dry conditions during the summer of
2020. About 2/3 of the provincial yield is harvested from the Northeast region.
An estimated 35,000 honey bee hives were used for blueberry pollination. Bumble
bees and Alfalfa leaf cutter bees (ALB) were also used to supplement
pollination. There was only minimal
winter injury in some regions. Monilinia blight pressure was low, and most
fields had few symptoms. The early days of bloom were good, with many good to
excellent days for pollination. The weather conditions were dry, and some
fields were showing symptoms of stress. Despite the dry conditions, fruit was
present on the plants, but berry size was small and weights were low. This
resulted in poor yields in many fields. Yields for some fields ranged from
complete loss to adequate, compared to previous crops of 4,000 lbs/acre or
better.
Michel Melanson, Environmental Services and Crop Specialist Unit (Blueberry and Apiculture), NB Agriculture, Aquaculture and Fisheries.
Potential New Varroacides for Beekeepers: Fenazaquin and Etoxazole show promise!
An effective Varroacide
must have high toxicity for the mites and a low toxicity for honey bees. A team of researchers in Alberta has just
published a report on work done to determine the potential of a range of chemical
treatments for Varroa mites. They
examined how effectively the treatments killed Varroa, balanced against how these
substances were tolerated by the honey bees.
The trial tested 16 active ingredients and 10 formulated products. Two active ingredients, fenazaquin (chemical
class: quinazoline) and etoxazole (chemical class: oxazoline) both proved
promising for control of Varroa mites and are seemingly safe for honey bees. A number of other compounds tested were effective
as miticides but further work is needed to examine honey bee tolerance.
The long-term
use of any one chemical, or family of chemicals, will result in mites
developing resistance. Ongoing control
of Varroa mites will require novel chemical treatments, careful use of current
treatments, and an IPM plan. Apivar® has
been used by Canadian beekeepers to manage Varroa mites for over 10 years and
is generally, still an effective product.
In spite of Apivar’s continuing efficacy, it is reassuring that new,
possible replacements are being investigated.
It must be
noted that this is preliminary work to determine the usefulness of these miticides
and they are not currently licensed for use by beekeepers. Further work, both inside and outside of the
lab, is needed and we optimistically look forward to hearing more as these research
studies progress.
Full article: Bahreini,
R., Nasr, M., Docherty, C. et al. Evaluation of potential miticide toxicity toVarroa destructor and honey bees, Apis mellifera, under laboratory conditions.
Sci Rep 10, 21529 (2020).
Connecting with ATTTA Specialists