>
> >If you had said "a direct measurement of the mite infestation rate of a
> _subset_ of the _adult_ population"
>
Yes, should have said : ) Although I find that there is not that much
variation between washes from any frame from the broodnest, nor day to day.
>
> > the likelihood of economic damage or colony -- no one has been able to
> establish a benchmark that can predict the tipping point with any
> precision, outside of the experimental situation where it was derived.
My experiment involves about 1000 colonies, which I try to keep alive year
after year. We've already discussed this on the List, and I get the
impression that many of us commercial beekeepers have figured out how high
we can allow mite measurements (by whatever proxy we use) to get before we
observe economic damage in our area, with our stock of bees.
There is no way that most of us will sample more than a few colonies, so I
look for an assessment method that is consistent and quick, since I don't
have time to keep returning to outyards to check back.
I've had a few people send me natural mite drop counts over time. They all
vary wildly from day to day.
For example, here are yesterdays and today's counts for the first two days
for a very small experiment I'm doing:
Day 1 Day 2
3 132
18 59
10 14
132 94
27 31
The above data were fairly extreme (last month I had a hive that dropped
222 mites one day, and 223 the next, but that sort of consistency appears
to me to be the exception).
I'd like to hear from the rest of you (lurkers send me data off list if you
wish) and Allen. Does anyone see natural drops to be consistent day to day,
or how many days do you need to average over to get a reliable figure for
"natural fall"?
Back to economic threshold, with regard to alcohol wash, if I observe mite
infestation rate to exceed 5%, I consistently see virus infection in the
broodnest. If I keep the mite infestation down to less than 2% at highest
(lower for most of the season), then the brood remains healthy.
Re Bob's opinion "I do not see the purpose myself. Sounds like a big waste
of time."
Don't know what you were referring to Bob--the use of MAQS, avoiding colony
stress in hot weather, or avoiding queen loss?
--
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
Guidelines for posting to BEE-L can be found at:
http://honeybeeworld.com/bee-l/guidelines.htm
|
