Dick Marron wrote:
>>>>>>>What personal experience have you had with this. How many times
in how many years have you seen this?<<<<<<<
All the papers that I have seen refer to work done by Otto Mackensen
back in 1943. So naturally I was curious as to what Mackensen actually
wrote way back in the middle of WWII. Mackensen decided to get to the
bottom of the question as to whether unfertilized bee eggs are ever
males.
At that time it was widely known that the African Cape Bee could
re-queen its colonies using the eggs from laying workers, and there
were a few isolated anecdotes of this trait popping up in other
African types. But Mackensen wanted to see if could happen with
regular "off the shelf" bees in the USA.
He took 3 types of bees: black Caucasian, banded Italian, and golden
Italian, and raised queens from them. He then trapped them in hives so
they could not mate. After 30 0r 40 days, these queens began to lay
unfertilized eggs. Out of fifty that produced brood, 21 produced "some
worker pupae".
He writes: "The exact percentage of eggs developing into females could
not be determined, since many ... are cleaned out of the comb before
they mature. It was estimated, however, that not more than 1 percent
of any of the eggs developed into workers."
He takes it one step further and raises 710 queen cells from the eggs
of one particular "virgin queen of the golden strain" . Out of these,
six turned into actual queens, or .85 percent. His attempts to get
these babies mated failed, however, so the actual number of real
laying queens produced by this method is, finally, zero.
What happened to them? Well, Otto isn't very scientific about that:
"Three of them were lost before we could make any use of them." One
was artificially inseminated and one was allowed to open mate but
"both were lost before they started laying". The other one was
confined to a nuc and not allowed to mate.
In conclusion, he writes, "more observations under the proper
experimental conditions are necessary to show how universal this
characteristic is among the bee races and varieties of the world." In
other words, I don't think he would approve of his work being used to
"prove" that this trait is "widespread".
* * *
Fast forward sixty years: H R Hepburn, working in South Africa, is
studying this trait in the native bees. In the region where he works,
there are three types identified by Ruttner: A. m. capensis, A. m.
scutellata, and an unnamed mountain bee.
Evidently, Ruttner was never satisfied with the classification of Cape
bees and scuts as separate types. "A geographic race may be defined as
a group of bees similar in morphology, behaviour and physiology, and
characterized by a specific geographical distribution". The
distinction was originally made in 1933 by Alpatov, comparing bees
1000 km apart (but not in the "transition zones").
Ruttner was unable to separate A. m. capensis from A. m. scutellata on
morphometric criteria alone. Hence, the attempt to classify them by
behavior and geography. The Cape bee had this weird trait called
parthenogenesis. But it now seems that parthenogenesis is just as
common among the "scuts"!
It turns out that there was never any real agreement on the
distinction between the Cape Bees and the "scuts". Studies by Maa,
1953 and DuPraw, 1964, concluded that all the bees of central and
southern Africa are a single subspecies of A. mellifera with a lot of
variation in color!
Hepburn concludes that the distinction between the various bees of
Africa, and especially between these two types, is artificial, based
on appearance and geography more than anything else. The whole notion
of human races has been discarded by biologists and it appears to be
suspect here as well.
* * *
Based on this information, it would hardly be surprising to find
parthenogenesis among the so-called Africanized Bees of the Americas,
since they are genetically most similar to the bees generally known as
Apis mellifera scutellata.
pb
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