The vine mealybug, Planococcus ficus Signoret (Pseudococcidae: Homoptera) is considered a primary vineyard pest. The presented work was carried out at a grapevine Feddemin at Village Fayoum Governorate, cultivated with the variety Ghribi to shed the light on seasonal fluctuation of population density, number and duration of generations of the vine mealybug, P. ficus as well as the effects of the main weather factors on the insect population . Regular biweekly samples from trunks, leaves and bunches of grapevine were taken for two successive years, from Nov. 2015 to Oct. 2017. The obtained data showed that P. ficus individuals were found throughout the year beneath the bark of grapevine trunk where the nymphs of the mealybug recorded six peaks in both investigated years. Adult females had five peaks during the first year and eight peaks in the second year. The highest numbers of P. ficus on trunks were recorded at the end of Aug. and in mid of Sep. for first and second year respectively. P. ficus infested only mature bunches and the highest numbers of the mealy bug on bunches were recorded at the end of Aug. in both years. The effect of maximum and minimum temperature on total individuals of the mealybug was positive and insignificant in the first years and positive highly significant in the second year. The effect of mean relative humidity was negative and insignificant. The combined effect of main weather factor on total individuals of the mealybug was insignificant in the first year while it was significant in the second year of investigation.