Dr. James Adams
JADAMS at carpet.dalton.peachnet.edu
Mon Sep 29 09:56:28 EDT 1997
And the discussion continues!
I believe it really boils down to native vs. non-native releases,
as several people have already mentioned, including myself. As John
Calhoun mentions, however, this is virtually impossible to regulate.
I can certainly imagine, and undoubtedly this actually *has* happened
numerous times, individuals transporting gravid females into areas
with appropriate foodplants but no standing populations of the
species. I will admit to trying this once, in my much younger and
naive days, with Mitoura gryneus. Never saw it in my hometown in
the Kansas City area, but there exists a very large population on the
University of Kansas campus. One spring I transported several
individuals several miles eastward and released them in a stand of
Juniperus virgineanus. Lousy weather followed, however, and they
never became established. Just as well, since the Red Cedar stand
has now been replaced by a sports complex!! Ah, progress . . .
> We must ALL adhere to logic. If a species does not occur somewhere, we
> can't simply pack some up and drop them off. Even if such introductions
> do not offset local ecosystems, these movements make it impossible to
> understand natural distribution patterns for researchers like myself.
Absolutely, though I can think of reasons for such introductions,
such as a species having historically occurred in an area where it
has since been extirpated by humans. We would then be
*reestablishing* populations that *should* exist. Do others agree?
One last point, however, that should be made is that such
introductions are *going to occur*, even if totally regulated and no
one purposely moves species around. Gypsy moth eggs hitch a ride on
cars, ctenuchine arctiid pupae get shipped around with bananas,
gravid females of species of all types of insects get moved around by
car, etc. I collected a specimen of Eudocima materna, practically
mint fresh, in Liberty, MO when I was a youngster. A natural
migrant? Almost definitely not (but we'll never know). The adult
was found at Guys Food Plant (owned by Borden now, maker of snack
foods), and peanut oil and numerous other products were constantly
being shipped in from foreign countries. My bet is that a pupa of E.
materna hitched a ride in with these products.
The modern age of human transportation has, by its very nature,
muddied the picture of natural ranges/movements of an incredible
number of species (including humans). I would hate to be an
archaeologist of another species hundreds of thousands of years from
now trying to put together clear pictures of natural ranges of
species. Lets hope our informational resources last a long time!!
More information about the Leps-l