Subject: Re: Cape Honeybees

From: [email-masked] (Andy Nachbaur)
Date: Fri, 27 Jan 1995 16:23:00 GMT

* off the B-list *
                    ----------------------------------------
Date:         Fri, 27 Jan 1995 09:25:16 GMT+2
From: MIKE ALLSOPP <[email-masked]>
Subject:      Re: Cape Honeybees

Greetings,

Allen Dick responded to my post "Re:Bee Introductions/Cape Honeybees"
with the following:

< I'm not familiar with the mechanism by which the capensis overrun
< the honeybees. In a few words, could you elaborate please?

With pleasure, but it takes more than a few words. As follows:

To start with, something on the Cape Honeybee (capensis). It is
reasonably gentle, a grey-black bee, a good producer and fairly
temperature tolerant. All good characteristics and for that reason
there have been a number of suggestions that capensis be introduced
for commercial production in other parts of the world (Israel, USA,
Mauritius). [Hence my question - does anyone know of capensis
introduced into the Americas].

But capensis are terrible if you put them with other bees, simply
because of certain unique attributes exhibited by capensis. [Which
make them irresistable to scientists; anyone know of introductions to
the Americas for study purposes]. It is these unique attributes that
have resulted in capensis overrunning African honeybees (scutellata)
in South Africa. We don't know all the details, but the general
scenario goes as follows:

1. A capensis colony is placed by a beekeeper in an apiary containing
scutellata colonies. Or a capensis swarm moves into the apiary. Or a
scutellata queen mates with some capensis drones on her mating
flight, thereby introducing capensis genes into the apiary. In the
last case the resultant hybrid workers behave much the same as do
pure capensis workers.

2. Once the capensis workers are in the apiary, by natural drift
(getting lost!) they get into all the other colonies, even if only in
very small numbers. [It probably only needs a half-dozen or so]. In
the case of the hybrid workers, they are already in a colony with a
scutellata queen.

3. Capensis queens can control (inhibit) capensis workers; scutellata
queens cannot. In a colony headed by a scutellata queen, there is a
pheromonal release as regards the capensis or hybrid workers. They
start developing chemically and physiologically; soon they have very
queenlike pheromonal signals and developed ovaries.

4. Somehow the scutellata queen is lost; either the capensis workers
kill her or (I think) the scutellata workers get rid of her.

5. There might be an attempt by the scutellata workers to rear queen
cells; if so these cells are eliminated by he capensis workers. The
capensis workers assume reproductive control in the colony, lay eggs
and produce brood. For the most part, the scutellata workers do not
contribute reproductively, and rather treat the capensis workers as
"false queens".

6. Because capensis workers produce parthenogenetically all brood
produced by these workers will be female. That is, they do not
produce drones like the laying workers of other bee races, but rather
they produce workers (or a new queen, if they should so choose). So
they produce more a more capensis brood, and more capensis workers,
which in turn produce capensis workers. The colony rapidly becomes
capensis.

7. The problem with these capensis laying worker colonies is that all
the workers think they are queens. All (most) of the workers lay
eggs, but there is less and less foraging. They consume all their
stores, and soon there are thousands upon thousands of eggs in the
colony (up to 50 per cell) but no larvae because there is no pollen
to feed larvae.

8. The colony gets weaker and weaker, and soon down to 1 or 2 frames
of bees. Then one of three things happen.
   (a) it absconds (and then, who knows what?)
   (b) it rears a capensis queen and goes back to a queenright phase
   (c) it dies out
In the case of our situation in South Africa, (a) and (c) seem to be
the most common. The whole process from the first drifting of the
capensis to the end of the colony takes from 2-6 months.

In summary, capensis are sweet bees but don't put them with other
races. Since this problem started in 1990, at least 75000 commercial
scutellata have been eliminated by capensis. And a further 54000
colonies which were capensis infected were killed in an effort to
stop the spread. Which did not work, and we still have a major
problem.

Hope that answers your query.

Cheers

Mike

  MIKE ALLSOPP
      HONEYBEE RESEARCH DIVISION
      PLANT PROTECTION RESEARCH INSTITUTE
      P/BAG X5017, STELLENBOSCH, 7599
      SOUTH AFRICA
  INTERNET : [email-masked]
  TELEFAX  : (021) 883-3285
  TELEPHONE: (021) 887-4690/1