Posted: 27/01/2015 at 13:42
The strips work well and give a good indication of how severe the problem is.
There are three main biological controls for thrips..
Mites which crawl around the plant feeding on thrips larvae (Amblyseius cucumeris)
soil-based mites that eat the thrips pupae (Hypoaspis miles)
nematodes that live in the soil and eat the thrips pupae (Steinernema feltiae). They need a min temp of about 8°C but the bacteria that they use to kill their hosts only works at about 14°C, so you can see where the problem is.