Squash is considered as one of the important vegetable crops in Egypt. Bemisia tabaci (Genn.) Biotype (B)(Hemiptera: Aleyrodidae) is one of the serious pests of squash cultivation and farmers are indiscriminately using high dose of hazardous chemicals to minimize pest damage that ultimately affecting the soil, ground water, environment and consumers health. Three squash cultivars namely Revera, Eskandarany and Mabrouka were cultivated during Nili 2011 and 2012 seasons in Qualubia Governorate to evaluate its susceptibility to the whitefly B. tabaci Biotype (B)  infestation. Also the present work dealt with the relationship between the whitefly populations and some plant leaves nutritional components. The results indicated that the cultivar Eskandarany was the most susceptible cultivar to whitefly infestation when treated with AZ+50% NPK and cultivar Revera was tolerant when treated with AZ+B+H+50% NPK. While the cultivar Mabrouka was moderately infested when treated with NPK. This work also observed the population densities of B. tabaci Biotype (B)  immature on the three tested cultivars was insignificantly negative with iron and manganese, On the other hand, the relationship with most bio-fertilizer treatments was insignificantly positive with phosphorous and potassium elements.