In my recent visit to Western Australia I had the oportunity to talk with a
young Bulgarian beekeeper. When talking with him about spring managment and
supplemental feeding he told me that he only add Cobalt, either in the form
of CoSo4 or CoCl2 to increase queen oviposition.

For the past two night I have been searching the web about this fact and I
think is time to ask the Bee-L crew about their knowledge about Cobalt in
Bee Diets.

On an australian honeybee nutrition review:

"The additional elements which are essential for animals, but for which no
estimates of their
contents in honeybees could be found include chlorine, iodine, bromide,
fluorine, selenium,
chromium, cobalt, arsenic, molybdenum, nickel,  silicon, tin and vanadium
(Underwood, 1997).
Determination of the concentration of these elements in the body of
honeybees would provide the
information needed to make an estimate of their requirement for bees."

On a Word document from an Egytian researcher:

"The effect of vitamin C and/or cobalt chloride which added with sugar syrup
on the haemolymph of worker larvae was studied.  Haematological examinations
indicate that the used concentrations have no determintal effect on honeybee
larvae"

"Mean fresh and dry weight in addition to water content in larvae, pupae and
adult workers from treated colonies with vitamin C and/or cobalt were more
than those from control colonies which fed on sugar syrup only"

"Early spring feeding with 0.6% vitamin C and its combination with 0.0015%
cobalt or 0.00075% cobalt alone, six time at 6 days interval considerably
affects the amount of brood reared and the quantity of honey and wax
produced by 1*st* hybrid of Carniolan honeybee colonies"

The other interesting finding is the relation betwen Cobalt and Vitamin B12.

On the other hand in study of
The Effects of Cations on the Activity of the Gypsy Moth (Lepidoptera:
Lymantriidae) Nuclear Polyhedrosis Virus
 the abstract states:
Fourteen cations were tested at a 1% concentration (wt:wt), as chlorides,
for their effects on the biological activity of the gypsy moth, *Lymantria
dispar* (L.), nuclear polyhedrosis virus (LdMNPV). Cupric chloride was toxic
to gypsy moth larvae. Ferrous and ferric chloride were inhibitory to larval
growth and development as well as to virus activity. Strontium chloride was
inhibitory to virus activity but had no apparent effects on gypsy moth
larvae. Six cations had little or no effect on virus activity (i.e.,
calcium, lanthanum, magnesium, nickel, potassium, sodium), whereas *four
cations (i.e., cobalt, manganese, ruthenium, zinc) acted as viral enhancers*,
as indicated by reductions in LC50s.



-- 
Juanse Barros J.
APIZUR S.A.
Carrera 695
Gorbea - CHILE
+56-45-271693
08-3613310
http://apiaraucania.blogspot.com/
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