Their host, distribution, morphological characterisoics their bionomics are described.The damages of S. juvencus imperialis are measured, and we have also surveyed the relationship between their occurrence and environment. The research indicates that the occurrence Peak of the adultsof I. leucospoides is two weeks later than S. Juvencus imperialis.I.leucospoides which oviposited its eggsinto the inside of eggs of juvenil larvaes of S. juvencus imperialis through their holes of oviposition. Therate of Parasitism of I. leucospoides is higher than 46 %. To control the population of S. juvencus imperi alis. I. leucospoides is the dey natural enemy.