The aim of this research was to study the effect of (Piper nigrun L.) extracts on eggs of (Sitotroga cerealle Oliv.). The methanolic ans acetonic extract were obteinded by two methods, Soxhlet and maceration. They were tested at different concentration on eggs of different ages. Independently of extracs and age of eggs, concentrations abov 5 mg/ml caused high mortality ofembreion. The mortality of larve during the embriogene period was higher them after eclosion. The extracts did not influence the period of incubation.