Insectistatic effect of parasitoid Diaeretiella rapae (M'Intosh) caused by sublethal doses of pirimicarb, cypermethrin and djmethoate was estimated by means of functional response^ The experimental results showed that the sub-lethal doses interfered with the foraging behaviours of the wasps.The effects mainly included.1. The wasps treated by sublethal doses spent more time to find their first host, and spent less time in the patch.2. The behaviour response of wasps to attack their hosts was obviously weaken...