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.