The toxicity of chemical insecticide; malathion, bioinsecticide; Beauveria bassiana and a plant growth regulator (PGR); Extratone at different pH values of spray solution and its effects on some biological parameters of adult Aphis craccivora under laboratory conditions were studied. Data showed that malathion at LC₅₀ revealed more effective in acidic water, also revealed that, the ideal pH for water used for spraying fungi is alkaline (pH 8-10). Data indicated that the toxicity increased as a period after treatment, Malathion gave the maximum toxicity at pH 4 followed by pH 5 while Biovar gave the maximum toxicity at pH 10 & 8 but Extratone gave the maximum toxicity at pH values 4 followed by pH 5. Malathion at LC₅₀ in acidic water decreased longevity, pre-parturition, parturition and post-parturition periods and mean numbers of nymphs of adult per female. Biovar decreased longevity, pre-parturition, parturition and post-parturition periods and mean numbers of nymphs of adult per female at pH values 10 & 8. Extratone decreased longevity, parturition periods and mean numbers of nymphs of adult per female but increased pre-parturition and post-parturition periods pH value 5.