From: "T & M Weatherhead" <queenbee@gil.com.au>
Date: Fri, 4 Jan 2002 07:22:09 +1000
To: <BiologicalBeekeeping@yahoogroups.com>
Subject: Re: Brood diseases

Erik wrote

> It is said, I don't know who, maybe Dee knows, that bees feed jelly up to a
> certain level in the cell. Thus making it more food per workerbee in bigger
> cells than in smaller.

The normal period for royal jelly feeding is about the first 48 hours of the
life of the larvae. After that they go onto a mixture of honey and pollen
often called chyle (think I got the spelling right). I have never heard of
the level theory. If you look at larvae the amount varies from day to day
and within the day. Probably more bees more food, less bees less food.

> Another effect seen, expressed
> again by David deJong at Apimondia in South Africa is that worker brood in
> bigger cells attracts varroa more than worker brood in smaller cells
> resulting in that you find a lot more varroa in bigger worker cells than in
> small cells when both are available in a colony, from tests they've made.

It was pity that I could not get to Apimondia in South Africa but the
changing of the dates stopped me from going. Is this in Apis mellifera or
in Africanised bees that this is reported from? I know that David de Jong
has done a lot of work with African bees as I have spoken to him on several
occasions on queen breeding work reported out of South Africa but that was
not on AM but African bees so it could not be applied to AM. What did he
say was the difference in attraction? Did the varroa discrimimate on cell
size thus inferring that varroa are able to measure the cell size somehow?

If, as is commonly accepted, the juvenile hormone is the trigger, then I am
at a loss to understand how cell size can dramatically change the
composition of the juvenile hormone in larvae within the same hive. I can
understand a change from hive to hive thus allowing for breeding for bees
that do not attract varroa by their juvenile hormone. This is maybe what is
happening with the SMR bees.

>I think it was made in 1995 already, think it is to be read on beesource.com
> somewhere. So the bigger amount of food can be the cause of this as we know
> some hormone in the jelly attracts varroa.

As varroa enter the cells just before they are capped, then royal jelly has
nothing to do with it as I see because they have not been feed royal jelly
for between 48 and 72 hours before the varroa enters the cell.

We know thas the varroa enters the cell and burrows into the food at the
bottom of the cell before later emerging to lay eggs. For any change to
happen here we would have to speculate that the smaller cell does not have
enough brood food therefore somehow upsetting the cycle of the varroa. But
this then leads to the conclusion that the smaller cell larvae is unfeed
because of the lack of food and thus is not as well nourished as the larger
celled larvae. This it makes it prone to more diseases as it is under
nourished if we follow the conclusions recently published on this group.

Trevor Weatherhead
AUSTRALIA