Releases harming resident populations

[Neil Jones]

In message <970929180433_2065158425 at emout05.mail.aol.com> Pavulaan at aol.com writes:
> In a message dated 97-09-29 10:02:56 EDT, Anne Kilmer writes (of butterfly
> releases):
> 
> << It's that it actually harms the butterfly populations it purports to help.
> >>
> 
> 
> This has never been studied nor documented to my knowledge.  I would love to
> see some literature references.  This is a fascinating subject, just ripe for
> a thesis (hint, hint, anybody out there?), and food for lively debate.  
> 
> Harry Pavulaan

Sorry to fill up your mailbox yet again Harry. :-)

I would suggest the following publication does contain information on this.
"A Review of Butterfly Introductions in Britain and Ireland" by M.R Oates and
M.S Warren. A contract report for the Joint Committee for the Conservation of
British Insects funded and published by the World Wide Fund for Nature in 1990.

It mentions the negative effect of population reinforcement in the Glanville
Fritillary butterfly (Melitaea cinxia) The problem being that the species
is prone to exhaust its food supply. One person even tried to  remove all
the parasites from the British colonies which are all confined to the Isle
of Wight off the South coast. The parasites are essential to keep the 
population in check. 

Incidentally the Glanville Fritillary (It would be called a checkerspot in the
US) got its name from a certain Lady Glanville whose will was contested by some
of her relatives on the grounds that her interest in butterflies demonstrated
that she was insane. The judge threw the case out.


-- 
Neil Jones- Neil at nwjones.demon.co.uk "The beauty and genius of a work of art
may be reconceived, though its first material expression be destroyed; a
vanished harmony may yet again inspire the composer; but when the last
individual of a race of living things breathes no more another heaven and
another earth must pass before such a one can be again." William Beebe