Date: Mon, 13 Jan 1997 18:32:01 -0800 From: Russell Elliott <relliott@geocities.com> To: cp@opus.hpl.hp.com Message-Id: <aabcdefg167$foo@default> Subject: Re: Red Spider mite?
Clarke Brunt wrote:
>
> Postage paid by: [Image]
>
> ---------------------------------------------------------------
>
> On 9 Jan 97 at 1:49, Russell Elliott wrote:
>
> > I was looking at my collection today, and to my horror,
> > a good 50% of my VFTS were looking very sickly. Looking
> > at them closely, most of the new traps that were emerging
> > were dead, along with most of the old leaves. To be honest,
> > I first noticed that they appeared to have more dead leaves
> > than normal about three weeks ago.
>
> Assuming you're in the northern hemisphere, then shouldn't your Venus
> Fly Traps be largely dormant? Mine go semi-dormant in a greenhouse
> with minimum 7C - not really growing, lots of dead traps (which I cut
> off) but still a few live ones. Still, I guess you are the only one
> who knows what your own plants normally do...
>
> > Anyway, I *think* the problem is red spider mite. The leaves
> > appear to have had their tissue "gouged" out (I'm only talking
> > about cuts about 1mm in length) and they appear flecked with
> > dead patches. I have also noticed tiny red dots on the plants.
> > Since I can't find my hand lens, I cant quite make out what
> > exactly these are.
>
> Red spider aren't all that red, and you really should be able to see
> them if you look closely enough. If you do see them though a
> magnifying lens, they usually have a dark spot on each side. I've
> never had these on my CP (I certainly do on cacti, and anything else
> they take a fancy to). As you mention 'cuts', I wonder if thrips
> could be the problem - another pest I have, though again not on the
> CP. These are linear insects, maybe 1-2 mm long, black or yellow, and
> often jump if disturbed.
>
> > I was wondering if anyone knew of any biological or environmental
> > control that is effective on them. I don't want to use Rogor,
> > as that chemical badly set back my entire Sarracenia collection,
> > and it is only now that they are just about recovered.
>
> There is a predatory mite for red-spider called Phytoseiulus
> persimilis which you can get in the UK (there is also one for
> thrips), but I doubt the effectiveness of these unless you can
> provide conditions more suitable for the predator than the prey. Both
> thrips and red-spider seem very resistant to any insecticides on the
> amateur market (in this day, if a chemical kills anything, then it
> seems to be rapidly banned). Yellow or blue sticky traps are quite
> good for thrips (which are attracted by the colour).
>
> --
> Clarke Brunt (clarke@brunt.demon.co.uk)
Clarke,
I live in Australia, its just that I use a geocities
account based in America. Anyway, thanks for the help
everyone, it appears that the infestation has nearly
been wiped out. All I did was raise the humidity to
about 90%, and that seems to have knocked off the mites.
Thanks to the person who suggested that, sorry I can't
remember who you were!
Thanks,
Russell Elliott
--*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-* ! Russell Elliott ! ! Seed Bank Director, ! ! Australian Carnivorous Plant Society ! ! mailto:relliott@geocities.com ! ! mailto:elliott@nexus.edu.au ! *-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
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