Re: insect problem
At 6:11 PM -0600 2/6/99, David Thornton wrote:
>I wonder if anyone can identify an insect problem that has wiped out my
>Colcasia esculenta and is now spreading over Xanthosoma.
>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.
David - This sounds very much like an infestation of spider mites, of which
there are several species. The description is quite good for this pest.
Word is that they drown in seven seconds, and they actually can be washed
off pretty easily, but with persistance, as they will return and repopulate
quickly from a few individuals or from eggs. Not being a big advocate of
heavy duty pesticides, I generally use a combination of 70% rubbing alcohol
with a mild soap, which proves quite effective. Test this on a small bit
of leaf first, however, because I have seen some cell damage result from
this. This does need to be applied several times at 7 to 10 day intervals.