The influence of powdered fruits of Foeniculum capillaceum Gilib. on the fecundity ofSitophilus oryzae was examined. The powder was added in paper bags to the rearing of the insects to prevent a direct contact. The sign i fi cant reduction of the fecundity of females was recorded. The sequent effect of activity of the powder was also observed. It resulted in the decrease of the fecundity of offspring generation - F2 reared on wheat grains without the powder.

The paper presents the stability problem of control systems composed of a fractional-order PI controller and a inertial plant of a fractional order with time delay. Simple and efficient computational method for determining stability regions in the controller and plant parameters space is given. Knowledge of these regions permits tuning of the fractional-order PI controller. The method proposed is based on the classical D-partition method.