If you are a new grower who has never experienced red spider mite, like me,
be sure to rule out this diagnosis first if you think you might have a
virus-infected Nepenthes. The two can look similar on some plants and
under some circumstances. If you want to avoid red spider mite, humidity
alone seems insufficient; wet the leaves when you water, too.
I had some problems on my Nepenthes gracilis and N. mirabilis recently,
which I thought might have been caused by a virus. The new leaves were
anemic, variegated and streaked, misshapen. Upon close inspection, the
symptoms turned out to be caused red spider mites - which are so small they
can hardly be seen. I tested Safer's soap on them first - a phosphate fatty
acid - spraying the leaves, but not the soil, and washing the soap off
after about 15 minutes. It killed most of the mites, but not all. The
plants recovered and grew several healthy leaves, but the symptoms began to
return after a couple months. I then tested them with pyrethrin. When it
appeared that there was no damage to the test leaves, I *really* let the
plants have it. That did the trick.
Scott
Madison WI