Poppy root weevils (Stenocarus ruficornis, Stephens 1831) control in opium poppy (Papaver somniferum L.).

Effects of insecticidal sprays on poppy root weevils (Stenocarus ruficornis, Stephens 1831) were assessed in small plot trials at three localities in the Czech Republic during two years (2011-2012). In addition, the effects of seed dressing were included into the assessment in one of the localities (Cerveny Ujezd). The levels of root damage caused by the insect pest larvae (expressed as number of bore holes per root) and yield got from individual treatments were compared. Sprays applied for 18 days after the first record of poppy root weevils in trials showed the highest effects on a decrease of the levels of root damage (40% of untreated control). In general, sprays applied at the date when SATF 14 value exceeded 20°C showed significant effects on decreasing the levels of root damage. The highest effects were usually recorded in sprays which were applied when SATF 14 value exceeded 100°C.