Thanks to all who responded off list and on
list to my inquiry.
I've had a few inquiry's off list about the
details related to this dieoff, so I put
together a short history of the dieoff
caused by Apis mellifera capensis in
South Africa, which became known as
The Capensis Calamity.
I will place any further information
on this subject that I locate, in the
Historical Honeybee Archives site,
in the file titled:
13) 1990, Bee Mortality - South Africa
The Capensis Calamity
During the 1970's the honey industry boomed.
Honey was exported and honey prices climbed.
Migratory beekeeping - the large scale movement
of hives - developed as part of the apicultural
industry to keep up with the demand for pollination
services and honey production.
There are two races of honeybees that occur
naturally in South Africa, Apis mellifera capensis
Escholtz (Cape honeybee) and Apis mellifera scutellata
Lepeletier (African savanna honeybee).
A. m. capensis is mainly restricted to he winter
rainfall region of the Cape as far as the Bokkeveld,
Cedarberg,Swartberg and Suurberg mountains.
A .m. scuteilata occurs in the summer rainfall
region north of the Roggenveldberg, Nuweveldberg,
Sneeuberg, Kikvorsberg, Stormberg and Drakensberg
mountains.
A hybridization zone occurs between these two groups.
In 1909 G.W. Onions discovered that queenless
workers of A. m. capensis lay eggs resulting in
female offspring rather than male offspring that
is the rule in all other honeybee populations.
In 1912 Onions describe the laying workers in
colonies of A. m. capensis, as a pseudo queen,
a little dark bee, a menace to the welfare of
the apiary and a fatal obstacle to queen-rearing
operations.
In 1954 Lundie stumbled by chance onto the phenomenon
that laying workers of A. m. capensis could invade
colonies of A. m. scutellata. Drifting as the sole
explanation for this was ruled out, as the number
of black bees in the colonies steadily increased.
Some careful notes were taken and he found that
these black bees, recognized by their larger abdomens
and characteristic attention from the other worker
bees, would invade strong as well as weak colonies.
Another important note, was that relatively large
areas of brood were found on the outside frames of
the brood nest. This never happens with a normal
A. m. scutellata colony.
In 1963 Anderson did some anatomical investigations
of A. m. capensis worker bees and found that the
number of ovaries in each ovary ranged from 5 to
59 with an average of 19.61. The size of the
spermtheca of a laying worker could reach a diameter
of about half that of a queen's ovaries.
In 1983 Johannsmeier warned beekeepers not to
introduce Savanna bees into the Cape region and
vice versa. In his experiences with Cape bees in
Gauteng, it was clear that the problem of invasion
of Savanna bee colonies by Cape worker bees
(pseudo-queens) could persist for some years, unless
drastic steps were taken to eliminate them.
In 1990 beekeepers moved some 400 A. m. capensis
colonies from the Lamberts Bay region in the Cape
to the Rust-der-Winter region in the Northern Province.
These colonies were incorporated into apiaries with
A. m. scuteilafa colonies.
In 1991 beekeepers took these colonies again to
the Rust-der-Winter area during the winter aloe
(Aloe greatheadii var. davyana) season where further
contamination with capensis bees occurred. In
the same year some colonies originally from the
Highflats in Natal that were moved to the
Langkloof in the Cape for pollination and returned
to Natal. Subsequently, they were moved to the
Douglas area in the Northern Cape during August.
In February 1992 Martin Johannsmeier found some
capensis laying workers in an apiary of a
commercial beekeeper in the Pretoria area. Queen
rearing in these colonies would not fourish
as in the past. On enquiry it was confirmed that
commercial beekeepers had observed the symptoms
of capensis laying workers a year earlier.
In 1993 Johannsmeier, compiled a leaflet for
distribution to beekeepers listing the symptoms
as follows:
Outside the hive: reduced foraging; many dead bees,
bees involved in fighting. Inside the hive:
scattered non-diseased brood with all larval
stages next to each other; queenlessness; black
capensis laying workers together with yellow-banded
scutellata honeybees; multiple eggs in worker or
queen cells; mature queen cells chewed open on the
sides. In an advanced stage of take-over these
laying worker colonies showed no defensiveness,
rapidly weakened and died out or absconded.
By 1993 about 54,000 colonies died or were destroyed
in the summer rainfall region. Honey production
was drastically reduced and honey prices almost
doubled. The total (as well as per hive) honey
production in South Africa dropped because of the
Cape bee problem, so that about 20% of the countrys
honey needs had to be imported.
In 1993 legislation was implemented to prevent
further spread by A. m. capensis laying workers.
The legislation prohibits the movement of honeybees
across a demarcated line. All honeybees north of
this line infested with Cape laying workers bees,
had to be destroyed.
By 1996 Cape bees had replaced many of the native
bees, but were found to be unable to endure the
harsher climate of northern South Africa. The sudden
loss of the bee population threatened fruit crops as
well as native plants.
In 1998 legislation was amended to prohibit the
keeping of Cape bees north of the borderline. It
also stated that any colony that was queenless,
or that had A. m. capensis laying workers, must
be killed within 72 hours.
But all the legislation and control mechanisms
failed to eradicate the problem. One of the reasons
may have been that only colonies that were moved
were inspected and killed. Colonies that were not
moved during this period were ignored but could
have been infected. Another reason may have been
that some beekeepers with infected colonies did
not comply with the regulation requiring that
infected colonies be killed.
Best Wishes,
Joe Waggle
http://pets.groups.yahoo.com/group/HistoricalHoneybeeArticles
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