Subject: Re: insect problem
On Sat, 6 Feb 1999, David Thornton wrote:
> It appears on the leaf surface and underside as small black
> flecks,rounded bodies, on closer look they appear as small grains of
> sand, some sand colour others black. I can see the odd one physically
> moving about. Eventually more and more of these flecks appear and
> strands of web like thread stretch between them.
As an addendum to other messages identifying this pest as spider mites, my
favorite method to kill'em is to use one of the horticultural oil sprays.
Just be sure it is not one of the heavy duty dormant oils, but rather one
of the ultra-fine varieties using a fine emultion of parafinnic oil. In
the US, I think one brand is "Sunspray" (Gardens Alive has their own
brand which is the same thing, as far as I could tell.).
I tested these oils on many aroids, and they all seem to tolerate it very
well. The oils also kill scale, and should be able to take out mite eggs
as well - just spray the surface of the soil and the pot. They work by
suffocating the critters, so generally they do not harm any beneficials if
you scare them away by shaking the plant. The treatment may need to be
repeated weekly for a couple of weeks.
The best prevention is to keep the humidity high. I never saw a spider
mite in North Carolina, and am fighting them on a regular basis in