Blackflies and Blueberries

146 views
Skip to first unread message

Carl Karasti

unread,
Jun 10, 2022, 10:05:40 PM6/10/22
to Ely Field Naturalists
Reports suggest that we have a plentiful crop of Blackflies.
For anyone who hasn't heard or who may have forgotten,
our love of Blueberries is not a valid justification for Blackflies
existing and biting chunks out of us in order to feast on our blood.
Blackflies do not pollinate Blueberries.
Here is a link to the research report that put to rest the myth that
had fooled many of us into accepting their violation of our bodies.

Carl Karasti


Abstract:
"It is often said that on the Canadian Shield, black flies pollinate the
sweet lowbush blueberry, because years with high black fly populations
also tend to be those with large blueberry crops. This folklore has
never been tested experimentally. Here we report on research designed
to test whether or not black flies can act as pollinators for two species of
ericaceous plants, sweet lowbush blueberry (Vaccinium angustifolium)
and leatherleaf (Chamaedaphne calyculata). In enclosures, black flies
may assist in leatherleaf pollination but there is no evidence that they
increase fruit set in sweet lowbush blueberry. However, we do not exclude
the possibility that in the wild, they act as opportunistic nectar thieves of
sweet lowbush blueberry."

Roger Powell

unread,
Jun 11, 2022, 1:12:44 PM6/11/22
to elyfieldn...@googlegroups.com
Dear Carl and other Naturalists,

Well, pop my bubble.  The story was such a good one -- something good about black flies.  Consie & I mentioned black flies pollinating blueberries the other day when we took our evening mosey with our dogs, and endured mostly mosquitoes but also some black flies.  Given that female black flies do crawl into blueberry flowers and drink the nectar, I can understand the origin of the myth.  I have some quibbles about the research design of the paper that Carl cited, by Hunter et alii (2000) (do black flies inside a mesh bag for 3-4 days behave naturally? does being inside a mesh bag affect the flies' abilities to carry pollen? do black flies with pollen need to get to a new plant within minutes to pollinate or is waiting for 3-4 days OK? maybe, if forced to wait 3-4 days, the flies just ate any pollen they carried), I doubt that my quibbles could really have affect the research results much.  I have looked up the papers that have cited the paper by Hunter et alii and none of those other challenge the results of Hunter et alii.  I have attached a pdf of the paper by Hunter et alii, which is 22 years old.  I would have hoped that such important news would have been better publicized.

So, who does pollinate blueberries?  Apparently, they require cross pollination, as demonstrated by the paper by Hunter et alii.  I found and have ordered a paper that reports on pollinators for several species of Vaccinium (the blueberry genus) and will distribute it when it comes.  I was able to download a paper on pollination of blueberry crops by Stubbs et alii (1994) in Maine (also attached).  Blueberry agriculture depended on honeybees back in the 1990s but the paper by Stubbs et alii showed that mason bees, like our resident blue mason bees (genus Osmia) will pollinate blueberries.  So, if you have blueberries close to your house, put up nest boards for mason bees.  We see them in our apple trees.  They are wonderful, solitary bees and need our support.

    peace , , , , ,

        rog . . . . . .

Roger A Powell
Department of Applied Ecology
North Carolina State University
PO Box 918, Ely, Minnesota 55731

tel. - 218-235-8808
https://cals.ncsu.edu/applied-ecology/people/rpowell-2/

   Husk at leve
      mens du gør det.
   Husk at elske
      mens du tør det.
              Piet Hein
--
You received this message because you are subscribed to the Google Groups "Ely Field Naturalists" group.
To unsubscribe from this group and stop receiving emails from it, send an email to elyfieldnatural...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/elyfieldnaturalists/CAEYZvGwQ_fzFknuK1Dgu%2BX0R%3DBpkaS6EnMU0-ngr45Q79AJV8w%40mail.gmail.com.

Hunter et alii 2000 Black flies and blueberries.pdf
Stubbs et alii 1994 Blueberry pollination, Osmia.pdf
Reply all
Reply to author
Forward
0 new messages