The changes in the seasonal population fluctuations as well as population of nymph and adult stages of the sugarcane soft scale Pulyinaria tenuivalvata (Newstead) were studied throughout 1997 and 1998 sugarcane growing seasons. P. tenuivalyata is a considered occasional insect pest attacking sugarcane plantations. It appeared in few numbers by the 3'^d week of May. Dynamics of the nymphal stage showed three district peaks occurred in May, September and November. Fluctuations of adult stage demonstrates three peaks occurred at 19th July, 20^t September and 1² November 1997, while three peaks were shown by 1^g August, 26^th September and 22^nd November in 1998 season. In general, insect population was significantly higher in 1998 than in 1997. Monthly variation rates (MVR) of P. tenuivalvata ensured that this insect species may develops three overlapping generations annually.