I have had good success against thrips using malathion on both Nepenthes
and Sarracenia (but not on other CPs). In both cases, I mix according
to label directions and spray both the bottom and tops of all leaves.
Because I use live sphagnum, I turn the pots on their sides when
spraying to avoid having the spray run onto the moss. One note of
caution is to avoid concentrations over the label directions. The one
time I was sloppy, new growth on the Sarrs. (trap leaves just about to
open, not the crown) were damaged. I typically repeat the spraying in
about two weeks to get the second generation.
Hope this helps.
Tom in Fl
PS. These are outdoor and garage/greenhouse plants, not terrariums.