Light and electron microscopic investigations were carried out on the fourth day imago of the house cricket, Acheta domestica L. treated with benserazid, or allatectomized. Introduction of benserazid (daily on the 1st, 2nd and 3rd days of imaginal life in 0.1 mg/g) failed to influence the development of the oocytes. However, benserazid in the concentration of 0.2 mg/g inhibited the growth of the terminal oocytes, while in 0.6 mg/g it completely blocked the development of terminal oocytes and vitellogenesis. The effect of benserazid proved to be reversible. Application of juvenile hormone analogue (ZR-515) prevented the effect of benserazid on the gonads of the crickets. Ultrastructural damages of the oocytes and follicular epithelium were the same in case of benserazid treatment and allatectomy, although the changes were more expressed in the latter case. The benserazid effect was found to be indirect, caused by damage to the interaction between the aminergic and peptidergic systems of the brain.