Jassid is a sucking pest occurring throughout the crop growing period on cotton in all the zones. The pest injects toxins into leaves while feeding which results in abnormal changes in leaves - marginal chlorosis and reddening. Since the pest severity is dependent on the occurrence of congenial weather conditions, we have devised weather based rules for weekly prediction of the pest severity. Based on severity prediction (based on ETL), pest management interventions and sprays can be taken up taking into account parameters such as pesticide efficacy, safety, spray interval (a gap of 7-15 days is advised between sprays), crop age and economics. analysis results performed on the 2 groups of natural living Jassids (Nephotettix nigropictus (Stal.) / Green leaf hopper) and the 2 groups of Jassids (Nephotettix nigropictus (Stal.) / Green leaf hopper) in stressful conditions showed significant changes in biochemical parameters concentration of hemolymph under the stress influence.