El-Khouly, A.S., Ali, M.A., El-Metwally, E.F., & Shalaby, M.S. 2004 Seasonal prevalence and time relative population trend of the sugarcane soft scale, Pulvinaria tenuivalvata (Newstead) (Homoptera: Coccidae) in Giza Governorate.. Egyptian Journal of Agricultural Research 82(3): 1099-1107.
Notes: Field experiments were conducted in sugarcane plantations Giza, Egypt, during the 1997 and 1998 cropping seasons, to monitor changes in the seasonal population fluctuations and populations of nymph and adult stages of the sugarcane soft scale Pulvinaria tenuivalvata. P. tenuivalvata is considered as an occasional insect pest attacking sugarcane plantations. A few numbers appeared by the third week of May. Dynamics of the nymphal stage showed 3 district peaks occurring in May, September and November. Fluctuations of the adult stage demonstrated 3 peaks occurring in 19 July, 20 September and 1 November 1997, while 3 peaks were occurred in 1 August, 26 September and 22 November 1998. In general, the insect population was significantly higher in 1998 than in 1997. Monthly P. tenuivalvata variation rates ensured that this insect species may develop 3 overlapping generations annually.