John Sewell writes:

    <<In unconnected posts Martin Damus offered the view that importing many
beestrains was good for variability, and James Kilty stressed the importance
of breeding from our local  bees. I'm sure they're both correct...
Can anyone help me understand this from a GENETIC viewpoint please?
I am aware there are a lot of other implications
to importation, but I am trying to understand (still) the scientific extent
of differences between the Apis mellifera honeybees, and the effects of
hybridisation between them. Is the cross between Greek Buckfasts and
English Buckfasts a new strain? What defines a 'race' of bee?>>

    A 'race' is basically a subspecies, that is, a group of organisms which
differ from their closes relatives, but not sufficiently to justify the
creation of a separate species. I realise that this is vague; what's a
species anyway? These things are perfectly clear in theory, but the system
was invented (for the convenience of scientists) before the discovery of
evolution. In practice things are not always that clear; it's obvious that
horses and donkeys, for instance, are separate species, but marsh orchids are
not so obvious.

    Basically, a 'race' of bees is adapted for a specific environment, and
may be expected to carry genes for traits which are suitable for that
environment, rather than for traits which are not. So, for instance, A.m.m.
tends to have a smaller broodnest than Italians, be slower to build up in the
spring (just what you want in a typical British spring!), to cut down
broodrearing when there's no flow, and to stop raising brood quite early.
Italians, on the other hand, raise lots of brood all the time, which is
probably what you want in a Mediterranean climate, but imagine if they were
raising all that brood in a nasty wet English autumn. They'd end up with no
stores, and starve, while A.m.m. would survive.

    I wouldn't worry about the genepool, frankly. There's plenty of evidence
of diversity in the original British bees, and they survived in relative
isolation for 8000 years or so (since we became an island) without evidence
of inbreeding. This will become a problem if you use II, and only use drones
of your own strain, or if you use a seriously isolated mating station, and
never import new blood. Otherwise, given the promiscuity of queens, and the
wandering tendency of drones, I suspect that you'd have the opposite problem,
and get more hybridisation than you'd want.

    It's difficult to think what to suggest in the way of introductory
reading; the problem here is that inheritance in bees works in a slightly
different way to inheritance in mammals, given the haploid drone (with only
one set of genes rather than the 'normal' two), and I'm only just getting my
head round it myself. I know I've seen some useful stuff, but can't place it
right now. Anyone else got any ideas?

Regards,

Robert Brenchley

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