Subject: | |
From: | |
Reply To: | |
Date: | Mon, 9 Jan 2006 16:46:41 -0800 |
Content-Type: | text/plain |
Parts/Attachments: |
|
|
Interesting article in January 2006 Bee Culture
In Research Reviewed by Steve Sheppard
"Selection and possibilities within honeybees -
Be careful what you select for."
-------->
A team of Italian and German researchers selected
lines of bees that tended to have either high or low
mite populations and then investigated whether
behavioral and physiological characteristics of bees
from these lineages could be correlated to mite
levels.
The results reported by the researchers showed that:
1) Mite resistance or tolerance as measured solely by
mite population levels was not readily correlated with
the various tested physiological and behavioral
honeybee characteristics.
2) There was no correlation between the tendency of
the bees to remove pin-killed brood (hygienic
behavior) and the mite infestation levels of the
colony
3) They was no correlation between the number of
non-reproducing mites (SMR) and the level of mite
infestation.
4) There was no correlation between grooming and mite
levels.
5) There was no correlation between the percentage of
damaged mites collected on sticky boards and the level
of mite infestation.
However, they did find that both brood area (number of
brood cells) and the average honey crop harvested were
higher in each year of the experiment in the so-called
susceptible colonies compared to the resistant
colonies!
The authors caution the reader that hygienic behavior,
non-reproduction of mites (SMR) and grooming may be
traits that have limited value in a selection program
designed to produce mite resistant honeybees.
They further caution that it may be difficult to
select for honeybees that produce both vigorous and
productive colonies, yet have slow growing mite
populations. Their rational for the latter statement
is that mite population growth appears to be tied to
brood levels. Thus, selection for low mite levels
could actually select for bees that produce smaller
amounts of brood.
For example, by using mite infestation level (mite
counts) as the only selective criterion, the
researchers may have inadvertently selected for high
and low brood producing lines of bees.
Thus, their resistant bees actually may have been bees
selected to produce less brood and to be less able to
sustain mite population growth. Consequently, they
also would have been less able to collect a surplus of
honey.
-------->
To summarize, low mite levels have limited value
unless accompanied by honey production and over all
colony performance. If one can manage to achieve low
mite counts and over all performance, then you may
have something.
__________________________________________
Yahoo! DSL – Something to write home about.
Just $16.99/mo. or less.
dsl.yahoo.com
-- Visit www.honeybeeworld.com/bee-l for rules, FAQ and other info ---
|
|
|