>Was that data (marked bees in collapsing colonies) made available anywhere?

I enter this discussion with trepidation, but will give it a try.

I have presented most of my findings in ppt presentations at some national
and state conferences, but have not yet published.
My data (which I have not yet finished analyzing) suggest that we still
have much to learn about bee drift to other colonies.

And there are two separate factors to consider: why bees attempt to enter
foreign colonies (independent of robbing), and why the guards allow some
bees to pass.  For the second question, the following study is of interest:
The cuticular hydrocarbon profiles of honey bee workers develop via a
socially-modulated innate process.  DOI: 10.7554/eLife.41855

Guard bees are sensitive to both the behavior and the odor of bees
attempting entrance to a colony.  And workers change the profile of their
cuticular hydrocarbons as they behaviorally "age."  Those exhibiting
"youthful" profiles tend to be more readily accepted.  Could it be that
some viruses suppress the change in CHCs, thus making drifted workers more
likely to be accepted?

Other studies suggest that the guards of diseased colonies are more
accepting of foreign bees.
In my own field study, I could not accurately quantify the above, since we
glued painted steel discs (some 6000) to the backs of young bees in
colonies starting to collapse from varroa/DWV, and measured the drift of
those bees to surrounding hives and apiaries by the use of magnetic traps
placed at the entrances.  So we couldn't place traps on the colonies with
tagged bees, since they would be unable to leave the colony.  That said, we
did later find a number of drifted metal tags on the bottom boards of
collapsing colonies, indicating that there was indeed near-colony drift of
bees between the closely-spaced collapsing colonies.

We also had stickyboards placed in mite-free colonies (via strong
treatment) to measure the amount of mite immigration into hives at various
distances, to see whether there was a correlation between drift of tagged
bees and mite immigration.  We found that some hives appeared to be
"drifted bee magnets," and some "mite magnets."  Some were both.

Regarding the drifting of tagged bees, there was a large drift of young
bees to other hives in the first days after tagging them, suggesting that
there is considerable drift of bees on their early excursions out of their
hive (the tagged bees mostly acted as house bees  after tagging, only
showing up guarding the entrance after about a week, and then later
starting foraging).  A number of other researchers whom I've spoken with
found the same thing -- that marked young bees drift a great deal.  This
may be important, since young bees tend to carry more mites.

> Perhaps it can address "reduced rates of return".
I strongly agree.  A "reduced rate of return" may not indicate that a bee
died in the field, but instead that it drifted to another colony.

But my most surprising finding was how frequently bees drifted to hives at
500 feet and 1/2 mile distant.  I'm still working on this data, but suspect
that it will suggest that we need to reevaluate the causes of bee drift,
since it's clearly not just to closely-adjacent hives.  I suspect that
olfaction is involved.

Randy Oliver
Grass Valley, CA
www.ScientificBeekeeping.com

             ***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software.  For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html