>
>
> >I didn’t see in the abstract where hive size was mentioned?
>
I deep brood chamber and a medium honey super.  This was in a warm area.

Of course I have questions on the study design.
They began with colonies exhibiting high daily mite drops -- at least 70
mites per day.  At that level, DWV had already likely become an issue, so
this experiment was more about trying to save colonies from an established
DWV infection by quickly reducing varroa, rather than about varroa control.
To do so, you'd need to really hit them hard immediately, as with the
Apivar strips.  Extrapolating from their graph, roughly 2400 mites dropped
in the first 11 days in that test group.  And with no brood interruption,
those colonies might be expected to recover over the next two months.

For reasons that I can't explain, they waited 8 days until they applied the
first OA vaporization, thus giving the amitraz strips an 8-day head start.

I can't understand why they caged the queens for 24 days.  One only needs
to cage them for 12 days to create a sealed-brood-free window to apply OA.
This excessive restriction of broodrearing hurt the colonies.  The colonies
received their only brood-free OA treatment on Day 24.  Those receiving 3
OA treatments got their other two earlier.  There was a big mite drop spike
for the brood-free colonies treated with OA on Day 24.

One thing to learn from this study is that to practice IPM for varroa, to
try to first understand DWV, varroa, and the effect of brood breaks.  Such
consideration could have improved the experimental design.


-- 
Randy Oliver
Grass Valley, CA
www.ScientificBeekeeping.com

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