Amongst various species of insect pests attacking the cotton crop, the sucking insect pests always remained a limiting factor. Among these sucking insects Jassid (Amrasca devastans Dist.) has great importance. Jassid is a very serious sucking pest of cotton which causes serious and significant yield reduction in susceptible cotton varieties. There a lot of research is carried out on the Physico-morphic characters and their effect on the sucking insect pests of non Bt-varieties but on the Bt-varieties there is no such type of research is carried out up till now. So it is needed that to carry...