EFFECT OF DIFFERENT PH VALUES OF SPRAY SOLUTION ON THE EFFICIENCYOF MALATHION, Beauveria bassiana AND EXTRATONE ON Aphiscraccivora

Abstract

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 postparturition periods pH value 5.