Re: Iris Borers
- To: Multiple recipients of list <i*@rt66.com>
- Subject: Re: Iris Borers
- From: "* G* C* <j*@erols.com>
- Date: Sat, 31 Jan 1998 17:48:47 -0700 (MST)
He
> I am not clear about this business of "inside" the plant. Do we mean within
> the fans, but still above the rhizome, or are we talking only about the larva
> that has entered the rhizome?
>
> If I am following this correctly you are saying that the borer larvae which
> are eating the plant from within are not inevitably affected by the systemic,
> even when great care is taken to achieve complete coverage of plant surfaces--
> which is supposed to render the plant tissues toxic-- and that theyshouldt be
> hit directly with the chemical to be eradicated. The suggestion, consistent
> with what we have heard before, is that they may be affected more in the
> leaves when young than when they reach the rhizome, albeit when they have been
> eating the Cygon treated leaves and their Cygon-eating fellows, for some time.
>
> Does this suggest that the systemic action is actually ineffective, that the
> chemical must be working only as a contact poison, which it is not supposed to
> do? Or does it suggest the rhizome itself does not support the systemic? Or
> that the plant absorbs only enough toxicity to kill young larvae? Or are they
> maybe just being drowned in Cygon?
>
Anner -- I'm afraid I would lean toward the contact-toxicity rather than
the systemic, based upon what I have experienced in my garden.
Griff Crump, along the tidal Potomac near Mount Vernon, VA
jgcrump@erols.com
