Abstract: Two biotypes of the whitefly, Bemisia tabaci, were recorded in Dakahelia and Damietta Governorates, Egypt. Biotype "B" or Bemisia argentifolii has a wide host range occurring on squash, tomato, cabbage, cotton and duranta plants, while Biotype ’Q” was recorded only on lantana plants. Squash plants attracted the silverleaf whitefly (SLWF), B. argentifolii, in both spring and fall plantations with significantly higher abundance in the latter. The correlation coefficient between SLWF life stages was discussed. Occurrence of the SLWF on squash plants indicated that the middle and lower leaves were preferred to nymphs and adults. Meanwhile all squash leaves were suitable for SLWF females to lay eggs, with higher deposition on the middle ones. In the field, B. argentifolii infestations were associated with silvering leaves disorder. The symptoms appeared after 21.5 and 17.5 days in the spring and fall plantations, respectively. Meanwhile in the laboratory, the same symptoms were observed 16.5 days after infestation.