Dave Cushman wrote:

>Hi Peter
>I do not know of a proper technical description to cover this, but the
>way I think  of it is that diversity is expression of different alleles,
>but those alleles need to be from the subset of the race concerned.
>
>If you get alleles that are specific other races that is where the
>trouble starts.

Dave,
I am not sure what you are thinking of in this second statement. Maybe some
examples would help to show us what you mean. 

So far as racial crosses go, Hepburn writes in his "Honeybees of Africa"
that a certain El-Sarrag tested crosses with Apis mellifera jemenitica
(which occurs naturally south of the Sahara but north of the range of
scutellata and adansonsii). He crossed this bee with a Carniolan and:

"the hybrids produced twice as much honey as the parental strains" 

In fact, the average for jemenitica was 1.6 kg, the average for carnica (in
that area) was 7.5 kg but the hybrids averaged 13 kg, almost ten times as
much honey as native jemenitica. However, El-Sarrag reported that the
hybrids were 

"significantly more aggressive than any of the parental strains"

The crossing of ligustica and scutellata produced what some might term as
the most successful honey bee yet, in terms of its ability to colonize over
an extremely wide area. And,-- it resists varroa, an introduced parasite for
which it can hardly have *evolved* resistance per se.

Peter Borst
Danby, NY  USA 

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