In a field experiment carried out in 1993 and 1994 seasons for evaluating the abundance of predators under chemical spraying applied on Nili squash. The most harmful insecticide was Malathion which re­duced total numbers of aphidophagous nymphs and larvae during spray­ing (3.27 individuals/leaf vs 9.03/leaf for the control and 2.05 individu­als/leaf vs 15.96 individuals/leaf for the control during 1993 and 1994 seasons, respectively). Supermisrona (mineral oil) was the safer com­pound and Sumicidin (fenvalerate) was intermediately affecting predator^. community. In a laboratory test, the mortality percentage of Euseius scutalis and Phaenobrimia aphidivora treated by Supermisrona were 18.75 and 13.62%, respectively, with insignificant differences from the control.