BEE SPACE
We all "KNOW" that bee space is between 4.5 mm and 8 mm and it
is also widely reported as being between 6 mm and 9 mm. However it
is not a "variable" quantity, it is either 5.3 mm + or - 0.5 mm or it is 9.0
mm + 0.0 mm - 1.0 mm. In other words there are two distinct bands of possible bee space and these
occur because in some situations the bees will work individually but in
other situations they need to be able to work back to back.
A gap of:- less than 4 mm... is too small
for any but deformed worker bees to pass through. Any spaces, cracks
or crevices of this or smaller dimension will be filled with propolis
or sometimes a mixture of wax & propolis and on yet other occasions
pollen may be mixed in with the filling (I suspect that this is for
reasons of porosity or possibly the transmission of light, but I am
not certain).
A gap of:- 4.3 mm is a
standard European spacing for wires in a Queen Excluder.
A gap of:- 5 mm if used between the wires
of a square mesh will make an excellent pollen stripper as the
workers can get through but a significant portion of pollen will be
stripped from their legs.
A gap of:- 5.2 - 5.4 mm is a spacing that can be used to
exclude or differentiate Drones as Workers and Queens will pass but
Drones cannot.
A gap of:- 6 mm Is the smallest gap that bees will leave
between adjacent comb surfaces (outside of the usual clustering
area) the bees can defend this more easily and they can work
individually within this dimension. The smaller gap around the
periphery of the nest, also renders the nest less susceptable to
draughts, and may help in maintaining humidity.
A gap of:- 7 mm not used by the bees themselves but some
people regard it as a valid bee space to use in some parts of
beekeeping equipment. If this spacing occurs between the side faces
of frame topbars they are the least likely to suffer from accretions
of wax. Frames spaced at 35 mm pitch (normal Hoffmann spacing) that
have topbars 28 mm in width give rise to this 7 mm gap.
A gap of:- 8 mm is a popular bee space among those that
design their own equipment as it falls midway between the 1/4" and
3/8" figures so often quoted in old books. I used to be keen on this
dimension myself but I have come to regard it as 'neither one thing
or the other' and now I favour 9 mm or in some circumstances 6 mm.
A gap of:- 9 mm is the usual space the bees will leave
between adjacent areas of capped brood this allows two layers of bees
to work back to back, usually in an oval pattern in the centre of a
frame.
A gap of:- more than 9 mm and we are into brace comb
territory!
A Gap of 10 mm is practical from a design point of view. with
the B.S. Brood frame at 215 mm (some are 216) mm and the Shallow Frame at 140 mm The
boxes are then 225 mm and 150 mm respectively this gives 1 mm above
the frames and 9 mm below (or the reverse if you are like me, top bee
space oriented). This may seem large but it only is this way with
fresh equipment. The grain in the frame side bars is vertical and
practically no shrinkage will occur in this direction. The box sides
however are grain oriented horizontal and the shrinkage will occur in
the vertical height of the box. So in use the space is often much
less than the initial 10 mm.
In all things there are exceptions... when it comes to the
gap between the frame bottom bars in the bottom box and the floor
surface underneath it, this is usually 28 mm or 31 mm in UK hives, but
it does not suffer brace or burr comb unduly, as the bees consider it
a similar situation to a wild nest in a cave.
Revised... 14 June 2001
