EN
The research was performed on sweet corn, Candle variety, in Terliczka near Rzeszow, in 2006–2009. In the period from the third decade of July to mid August, when the number of Diabrotica virgifera beetles was the highest, their daily activity on plants was observed at 6.00 a.m.; 9.00 a.m.; 12.00; 3.00 p.m. and 6.00 p.m. On the basis of performed research it was found that the activity of beetles D. virgifera is the highest at 9:00 a.m. and 6:00 p.m. Thus, observations of the beetles chemical control, as well as observations related to that pest’s presence in crops, should be performed at that time.