No Subject

The pupae may be vunerable, as I said I haven't seen any research, the
supplier may be able to tell you, it depends a great deal on the nematode,
but I would expect the best time to apply would be when the larvae is
present, that may be a very short window of opportunity.

I would not expect the nematodes to be able to attack larvae inside the
rhizome without an open channel to the soil

To the best of my knowledge there are no artificially engineered nematodes
available commerially. They are not alien (to most areas) and can be found
normally at very low numbers in healthy soil where they form part of the
soil ecosystem. The very act of gardening is as much scewing around with the
natural order of things. If these borers are at a level where you feel you
need to treat them then I am sure that the nematode would have the least
detrimental effect on your ecosystem. They will any insect they can get into
but as you can see by how much care is required to get borers for example
you are unlikely to have a large effect on beneficial insects by chance.

All living creatures can mutate, most mutations are bad and result in the
organism dying. Nematodes are quite advanced creatures and those that kill
insects have many specialisations that allow them to do that and prevent
them from infecting anything else. Most mutations would result in the
nematode dying any others would not be able to make it into anything other
than a nematode that kills insects. Something big (relatively) like a
nematode is far less likely to mutate into something dangerous like small
things (say the flu virus) do just because it is so complicated.

Simone Clark 
Canberra Australia

The opinions expressed above are my own, not those of my employer

At 01:48 PM 3/11/97 -0500, you wrote:
>Simone said:
>
><<  I think I mentioned  before when this topic came up that I thought it
>would be very unlikely that  foliar spaying would kill iris borers currently
>in fans, you must spray the  soil when the larvae are there, so timing is
>very important. >>
>
>Simone, please, would you expect the pupae to be vulnerable in the soil?
>Would you expect the nematodes to be able to attack the larva in the rhizome
>if the rhizome had not been opened to the soil by the chewing larva? If not,
>do I understand correctly that the only time the insect is vulnerable to the
>nematodes would be during the period between the time the larva leaves the
>rhizome and burrows into the soil, and the time it enters into pupation? 
>
>Also, should there be any concern about introducing quantities of such alien
>and possibly artificially engineered life forms into an ecosystem? Can they
>mutate? All my instincts say this is screwing around with the natural order
>of things, so to speak, and so it is suspect on the face of it.
>
>The previous discussions of this subject may be followed in the Archives at:
>
>http://www.mallorn.com/lists/iris-l/
>
>Just search and use that fine keyword "nematodes."
>
>Anner Whitehead, Richmond, Va
>Henry Hall  henryanner@aol.com 
>
>
>
>
Simone Clark
Nematode Project
CSIRO Entomology

simoner@ento.csiro.au
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