In Article <firstname.lastname@example.org>,
>In article <aquilla.1147501518F@sadye.emba.uvm.edu>,
>email@example.com (Tracy Aquilla) wrote:
>> Before addressing this issue, I'd like to state my opinions so as to avoid
>> anyone jumping the gun and possibly flaming me. First, I think eradication
>> programs are a huge waste of time and money. It is impossible to eradicate
>> an insect; at least it has never been done before, as far as I know.
>Tracy - I generally thought of you as a knowledgeable person.. but here
>you fall short. Many insect pests have been eradicated from certain
Thanks for (previously?) thinking of me as knowledgeable. While I have had
no direct personal experience with cotton, I am quite familiar with numerous
eradication programs. Furthermore, since you question my knowledge in this
area, I guess I should point out that I have several years of training and
research under my belt and hold advanced degrees in entomology and genetics
from the entomology department at UC Riverside. I am not just speaking as a
"knowledgeable person" but as a professional trained in the field of
agricultural pest control. There are a few rare cases where eradication
programs have been deemed "successful" by bureaucrats. However,
entomologists in the field disagree on whether or not these programs have
been successful. Some entomologists may try to convince you that eradication
is cost effective, but these are usually the guys who earn their living from
these programs. Certainly the pests in question have not been completely
eliminated from the the areas in question, and even with constant monitoring
and occasional necessary insecticide applications, these pest populations
frequently return to economic levels. If an eradication program is
discontinued, the insect returns to pest status very quickly. In nearly
every case it is debatable whether the annual cost of the eradication
program is offset by the benefits. There may be one or two exceptions.
>I'm no expert in this but I know that the screw fly in the desert
>southwest has been eradicated - and very clearly the boll weevil has been
>eradicated from large areas of the southeast.
Speak to an entomologist in one of these areas and they'll tell you that
these species are found occasionally in areas from which they've supposedly
been "eradicated". Since the screw-worm eradication program began (in the
early 60s?), there have been several rather serious outbreaks of screw-worms
in the southern US. Even with constant vigilance, there are infrequent small
outbreaks; this pest has not really been eradicated (see eradicate in your
dictionary). In order to maintain control the program must be ongoing,
meaning it costs lots of money every year. Even if they were to be
completely eradicated, they would soon be re-introduced. The case of the Med
fly is another example that is often touted as a success. We've been trying
to eradicate this pest for over fifty years and it's still here.
>The reason the boll weevil can be eradicated is because of its very
>limited host range. essentially cotton. If you can control it in cotton
>you will eradicate it. If you lose the battle on even one field you lose
This last statement is exactly why eradication generally doesn't work. There
are no insecticides that will kill 100% of the field population, even when
exceeding the application rate listed on the label. In fact, the boll weevil
is a particularly tough case for chemical control, since the pest burrows
into the squares and bolls, making it difficult to hit with insecticides.
Complete eradication is not only unattainable, such attempts are extremely
wasteful of valuable resources that could be used much more effectively
elsewhere. In the US we have been battling this pest for nearly a century.
The idea that we can win this war with nature is absurd! Will we never learn?
>It it has been shown conclusively that non-chemical methods do not work!
>Organic farmers are deillusional if they think otherwise.
Now you've really stepped in it! First, in regard to the scientific method,
a negative experimental result generally does not provide conclusive
evidence of anything. Secondly, THE most successful eradication program of
the century is that of the screw-worm in the southern US (east and west).
The success of this program is directly due to the ongoing annual release of
sterile male flies, NOT insecticide applications. I'd say non-chemical
methods are the ONLY ones that DO work! Even this pragram doesn't have 100%
Hasn't eradication of the boll weevil been attempted before in Texas;
why would anyone expect it to work this time around? When calcium arsenate
didn't work in the first half of the century, chlorinated hydrocarbons were
used. Boll weevils developed such a level of resistance to these
insecticides that many safe and effective organochloride compounds were
deregistered. Next the second and third generation compounds were used (i.e.
organophosphates and carbamates). Some of the most toxic compounds
synthesized by man have proven to be ineffective at eradicating this pest.
Therefore, it seems clear that attempts at complete eradication are
pointless, and in fact, complete eradication is unnecessary. It is only
necessary to reduce the pest population to a stable level below the economic
threshold. Finally realizing this, we turned to our last resort: cultural
control. I think the success of the eradication program in the southeastern
US can mostly be attributed to cultural control. Pheromone trapping, early
planting, using early-maturing varieties, and other similar cultural methods
are really what have allowed us to continue producing cotton in the cotton
belt of the US. These are all non-chemical methods of pest control, and they
work fairly well.
Concerning your second statement above, I think many classical
biocontrol programs have proved to be much more successful at maintaining a
stable sub-economic pest population than any eradication program ever
conceived. I'm not convinced that IPM couldn't solve this problem more
effectively and more economically than a chemical eradication program might.
In fact, attempts at eradication may even select for a population that is
resistant to currently effective insecticides (as has been shown in the
past), compounding the problem and making the pest even more difficult to
control with chemicals. There are well over fifty different parasites,
parasitoids, and pathogens of boll weevils. By combining some of these with
the currently used cultural methods, I think we could obtain adequate
control more effectively and for less cost than by widespread aerial
spraying with malathion. Same goes for the Med fly. After years of arerial
spraying to no avail, they are finally seriously considering using
biocontrol (in CAL).
FWIW, my opinion is that this program in Texas is politically motivated.
There are literally over 100 insect pests of cotton, and it has (one of?)
the highest rates of insecticide use of any crop in the US. There are quite
a few cotton growers in Texas. If the state were to spray widely on a
routine basis, the cotton growers would have a lot less to worry about and
their insecticide use would be subsidized. The only real obstacle to this
gravy-train is the organic cotton growers.
In closing, I'd like to point out that I am not an anti-pesticide freak.
In fact, quite to the contrary, I have frequently posted to this and other
related groups expounding on the virtues of products such as DDT. However,
based on what we have learned about the various negative impacts of
widespread, indiscriminate pesticide use, I think we need to dummy-up.
Chemical control is an effective tool, but it is not the cure-all the
previous generation believed it to be. The wave of the future in pest
control is IPM. Lecture over.
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