Hi Allen & all

A question or two, if I may.

I would assume, without knowing for sure, that varroa mites are sized
the same in South Africa as elsewhere in the world. Then accept that
today our "natural" wild scutellata swarms construct cells between 4.3
and 4.7mm - of own choice.

Surely that would seriously inhibit varroa propogation?

I would say that any wild swarm here, if properly examined, would
exhibit varroa. If varroa can complete its breeding in these smaller
cells, they would, ipso facto, make it in 4.9mm cells?

Or are the varroa here only using drone brood?

Separately, what about "old" dark brood cells that have been
contracted by cucoons? What "size" are these?

Just in passing, as mentioned earlier, I recently examined in great
detail a significant number of trapped "wild" scutellata swarms. The
following observations can be made in respect of cell size and varroa:

1. The 25mm foundation strips can be viewed as "transition cells" as
the bees slim the cell size down when drawing in open air.
2.  Evidence of varroa was minimal.
3. Varroa - when present - can often be seen on the backs of these
bees.
4. Other pests/diseases are minimal. It is, of course, mid-winter and
dry. An occasional hive beetle and braula is seen. No brood diseases
were present. These "wild" bees have, of course, not been treated for
anything whatsoever.

Barry Sergeant
Kyalami
South Africa