🚀 go-pugleaf

in article <10794@sdcc6.ucsd.edu>, rabani@sdbio2.ucsd.edu (Ely Rabani/D Smith) says:
> 
> I'm curious about the claim that wild flies 'evolve' to recognise
> steriles.  Where did you encounter it, etc.,.

My information comes from the lab notes prepared by Dr. J. Gordon Edwards
for the Ent. 101 class at San Jose State U.  The exact quote:

    This method [releasing sterile males] has been used against
    the Screw-worm Fly in Florida and Texas, the Melon Fly on
    the island of Rota in the Pacific, Oriental Fruit Fly in Guam
    and in California, and Mediterranean Fruit Fly in Southern
    California.  It is extremely expensive, and the targets appear
    to develop "resistance" of various types, after which the
    method becomes ineffective.

He doesn't go into details about developing resistance, but I'm sure
it's the same sort of natural selection you see with pesticides.
Most of the wild flies will breed with the sterile ones, leave no
offspring, and thus leave the picture.  A few females, however, will
mate with other fertile flies.  Sometimes this will be purely by
chance, and their offspring will be taken care of by the same
technique next generation.  Some of the females, however, will choose
their mates based on differences between the sterile population and
some of the males in the fertile population.  Maybe the sterile males
don't spend enough time hanging around the undersides of tree
branches, for example, or maybe they don't smell quite right, or
their hair is too long.  Whatever the basis for mate selection, this
behavior will be passed to the next generation, who will also tend
to pass up the sterile flies.
offspring, and thus leave the picture.  A few will mate with

> Malathion does have the effect of throwing off
> predator prey balances in the insect world  (Research done by someone at
> UCDavis.)  The point I would like to make is that no one at the state
> agencies responsible for evaluating the environmental impact of spraying
> ever did anticipate/consider this.

I think it's unlikely that they failed to think about this; I have
heard people (though not from gov't agencies) suggest that crop
yields might be less in sprayed areas because of lack of pollenating
insects.  Most likely what happened (though this is pure speculation)
is that they thought of it, did a quick seat-of-the-pants guesstimate
of how much other insect populations would be affected, decided that
the benefits outweighed these risks, and further decided that the
time it would take to get some good data evaluating the risks would
be longer than they could afford to wait.  All the politics involved
probably motivated them to keep quiet about the subject in public.

> The cheif scientist responsible for drafting the report on malathion's
> effects on humans for (I beleive it was) the State Dept of Agri had his
> first report returned to him by superiours and then resigned or was
> fired over conflicts over rewriting it with numbers that were more--for
> lack of a better term--aesthetically pleasing.

I, in turn, am curious about the source for this information.

It seems like the environmentalists are in an all-out battle with the
government and pesticide industry, with both sides engaged in a
propoganda war.  In the process, the general public suffers, both
sides lose credibility, and neither side can advance its aims as well
as it could if the two sides were working together.
-- 
Mark Isaak    {decwrl,sun}!imagen!isaak  or  imagen!isaak@decwrl.dec.com
"Convictions are more dangerous enemies of truth than lies." - Nietzsche