Dear All

What with all the messages about South African bees and pests, I
thought I had best comment, and in some cases set the record
straight. I am not, in this message, supporting the conclusions with
published references or data, but they available (in most cases):

(1) The development time for both Cape bees (capensis) and
African bees (scutellata) is just about 19 days. I guess it is not
known as to why this is shorter than in European bees, but it
probably relates to differences in larval feeding. The critical
component is that the post-capping period in these bees (when
varroa can reproduce) is much shorter than in European bees,
about 10.5 days.

(2) Researchers in Europe have been looking at the short post-
capping period of capensis as a possible means for varroa
tolerance for almost two decades (and are still working on it). It
certainly reduces the capacity of varroa to reproduce in worker
brood, but does not eliminate it.

(3) The varroa mite is clearly causing real problems to both
capensis and scutellata in South Africa. How severe these are is
hard to say, but severe enough for many beekeepers to use
varroacides on all their colonies (the wallet test). As varroa has
only been in SA since about 1995/6, it is only now reaching some
parts of the country. Hence, in many areas the wild population
remains varroa-free and, if varroa is present, it is too soon for it to
be causing a problem. In areas of the country (both capensis and
scutellata) where varroa has been with us for 4-5 years, we are
seeing varroa causing colony mortality.

(4) One of the projects of our Varroa Research Programme has
been to continually remove drone brood from colonies, and to
monitor mite reproduction in these drone-brood-free colonies. The
mite population continued to increase, albeit slowly, and the
colonies collapsed. Conclusion: varroa reproduces okay in Cape
worker brood.

(5) There is lots of data to show that the natural cell size in "fresh"
capensis and scutellata colonies (wild colonies) is pretty constant
around 4.85-4.90 mm. Cell size and the bees get smaller in older
combs.

(6) The Large Hive Beetle is a very minor problem in SA.
Occasionally, however, they are very destructive, and you can find
20-100 of them in a colony. The bees have no defence against
large numbers of beetles, and the beetles destroy the colonies.
The bees defence seems to be primarily behavioural: they limit
beetle accessw to the colony by building very think propolis
shields, with holes big enough for bees but not beetles. It should
be noted that these beetles are incidental pests of bee hives, and
not obligate pests like small hive beetles. I guess that, as in the
case of small hive beetles, it would be wise not to get large hive
beetles to the USA.

(7) At present (in Cape bees) we are not finding any good evidence
of (traditional) "hygienic" behaviour having any influence on
tolerance to the varroa mite.

I hope that clarifies certain issues.

best regards

Mike Allsopp
Stellenbosch