I just received a copy of a study, "Energetic stress in the honeybee Apis
mellifera from Nosema ceranae infection" by Christopher Mayack, Dhruba Naug,
which, in part says,
"Nosema is a microsporidian pathogen that infects the honeybee gut and is
known to cause a suite of metabolic changes in the host (Bailey, 1981).
Infected bees are known to have lower levels of pro-tein, resulting in a
reduced hypopharengeal gland (Malone and Gatehouse, 1998; Wang and Moeller,
1970; Wang and Moeller,1971), as well as altered fatty acid composition in
the hemolymph (Roberts, 1968). It has been less commonly suggested that
Nosema also uses carbohydrates from the epithelial cells of the honeybee gut
lining (Higes et al., 2007; Liu, 1984). The demand placed on the host with
respect to carbohydrate is especially interesting because it is the most
fundamental source of energy and bees, due to their high metabolic rates
that come with ?ight (Neukirch,1982), have a high demand for it. It is also
important to note in this context that the foragers, which are likely to
have the highest energetic demand, are also the ones with the highest Nosema
load (El-Shemy and Pickard, 1989; Higes et al., 2008)...
The study examines a number of interesting aspects of the effects of nosema
infection and their implications.
The passage above is of particular interest to me in that it refers to "a
reduced hypopharengeal gland ...as well as altered fatty acid composition in
the hemolymph... "
We have discussed the feeding of protein supplements and the reported
positive effect on nosema-infected colonies. While carbohydrate sufficiency
is quite obvious, deficiency in protein or amino acid nutrition are far less
apparent, and this knowledge would seem to me to support the notion that
feeding supplements when in doubt cab be an appropriate action.
I have looked into the cells of a lot of brood frames in the past weeks and
often see only two colours of pollen: yellow and orange. I don't know for
certain what the source is although I have some guesses. No matter, I do
know that they are not tree pollens -- we only get tree pollens in the
spring -- so these pollens are likely somewhere far down the list of ideal
pollens, and I'm betting they are deficient in some important aspects.
In our area, we see the maximum performance from our bees in spring, then
declining brood rearing. This is widely considered to be normal and
seasonal, but I think it is as much related to the changing pollen
nutritional profile as to the other factors (population 'peak', season,
flows, etc.)
This year, I fed Global's 15% pollen patties all summer and notice that the
colonies not only eat them, but that I am getting enhanced performance from
my hives over what I would normally expect. Unfortunately, I have not run
controls, because this did not start out as an experiment, and I have not
checked yet for nosema, either.
***********************************************
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
Access BEE-L directly at:
http://community.lsoft.com/scripts/wa-LSOFTDONATIONS.exe?A0=BEE-L
|
