Traffic in plants and plant seeds
viceroy at gate.net
Sat Sep 19 02:03:12 EDT 1998
John Grehan wrote:
> I am curious to know what the intention is here. Is Paul saying that without
> eucalyptus the monarchs would have had nothing else to roost on because
> people would have not planted anything else? If people did plant local species
> there would perhaps have been no need to introduce eucalyptus?
> Unelated in some way, but I recall that in some places (parts of Africa I
> eucalypts have been planted as the expense of local species, but the
> eucalypts have been so efficient (if that's the word) at water intake that
> the surrounding areas have suffered water depeletion and consequent
> reduction in the survival of other species (this is just recollection so I'm
> happy to be corrected).
> Sincerely, John Grehan
Dunno about Africa. The Melaleuca which has taken over the Everglades in
South Florida is a eucalypt. Remarkably beautiful, and a good source of
nectar for the atala butterfly, Eumaeus atala, once thought extinct.
Because of the vast plantings of melaleuca and Brazilian pepper
(Schinus terebinthefolius), both once highly regarded by USDA, enormous
quantities of nectar are available to the honeybees. These are therefore
brought in giant truckloads to Florida for the winter, where they can
pass around their parasites and diseases.
Varroa mites, tracheal mites, and now the small hive beetle were given
a head start by this custom. Can we blame the trees?
The state of Florida is now trying to get rid of the trees, but
continues to welcome the traveling honey bees.
The atala, meanwhile, perhaps because of this generous year-round
supply of nectar, perhaps because of the absence of its natural
predator, tends to overwhelm its (very expensive) host plant.
While kudzu is not yet established here, it's only a matter of time. I
talked to a South Florida gardener who has brought cuttings and trained
the vine to a trellis in her garden. When I advised her to get rid of
it, she explained that she was being careful. That's nice.
As I write, the white-footed ants, now a pan-tropical pest; once an
island species in Japan, are swarming ... gathering around my lamp and
landing on my white robe. They will be of interest to all of you, I
imagine. They're a structural pest, with huge super-intelligent colonies
which can bud, as well as reproducing by means of winged females,
already mated at flight. If you visit an infested area, you can take
home enough ants, in the debris around your trunk and windshield wiper
slot, to seed your neighborhood and the areas you drive through.
I hate to think what they will do to Florida's nursery business.
They are of interest on this list, because they tend insects, and may
well bring back the Miami Blue (wouldn't that be nice).
Once Man has colonized a place, it's all over for the indigenes, and
that goes for the bugs, the plants and the furry critters.
It behooves us therefore to consider carefully as we replant an area to
our liking, and to practice big-picture gardening.
As we are ourselves exotic, except, I suppose, in a small section of
Africa, we need to surround ourselves with our commensal plants and
animals ... and the rats, roaches and weeds tag along uninvited.
But I question the wisdom of providing exotic trees to serve the needs
of insects, exotic or native. If we are deliberately tweaking the
environment to favor one insect over another, for purely aesthetic
reasons, perhaps we need to rethink our strategies.
Has California no butterflies besides the Monarch, that it must
sacrifice its natural landscape to accommodate a very common (though
delightful) butterfly? :) Yes, yes, I know, they migrate.
And surely, as John wisely points out, they can plant other trees. Any
monoculture is doomed; something will come along that the eucalypts
don't like, and off they go.
I live in a land so assailed and invaded by aliens that there is little
space left for the indigenes. Even our alleged Native Americans are not
in fact native to this part of the planet.
Our water is filled with fish and plants dumped from aquariums and
released by failed aquaculturists. Few of our grasses are native. Our
forests are filled with trees and vines from Australia, Africa, and
Asia. Perhaps, as Paul suggests, they're just fine this way and we
should simply admire the handsome result.
My concern is more the herbicides and pesticides used to combat these
rampant "pest" species. These are not only killing the butterflies I
love; they're killing me.
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