C J Campbell wrote:

"Doug" wrote in message
om...

| I'm not saying there aren't times when insecticides are appropriate.
| But not always. Biological systems are very complex. We humans just
| don't know and don't have all the tools to do the right thing. Nature
| does. Just give it time.

Sure, if you don't mind the Dutch elm becoming extinct.

Since there has never been a "Dutch Elm" species I don't see why anyone
would mind if it became extinct.

There is a fungal infection called Dutch Elm disease to which different elm
species show varying degrees of susceptibility, but not to the point of it
causing extinction. The American elm is particularly susceptible, but would
not have become extinct given the length of time it takes for the fungus to
kill the tree. Even if infected, new trees may already reproduce before
they are killed by the fungus. In a natural setting the more susceptible
species will have their range reduced and there will be selective pressure
to increase resistance until stability is restored. The introduction of
resistant hybrid strains is an artificial attempt to speed up this process,
but extinction would not have been likely in any event.

The problem we perceive is largely manmade with the deliberate planting of
row upon row of the same species of elm down city streets and in replanted
forests followed by the inadvertent introduction of the fungus in imported
wood from Europe.