Masoodi, M.A., Sofi, A.R., Bhagat, K.C., & Koul, V.K. 1996 Relative susceptibility of apple cultivars to San Jose scale, Quadraspidiotus perniciosus (Comstock).. Pest Management and Economic Zoology 4(1/2): 119-121.

Notes: Susceptibility of ten cultivars of apple, namely Ambri, American Apirouge, Benoni, Cox's Orange Pippin, Golden Delicious, Red Delicious, Red Gold, Rich-A-Red, Royal Delicious and White Dotted Red to Quadraspidiotus perniciosus was studied by estimating the population of crawlers on the twigs. The degree of susceptibility of the varieties was assessed on the basis of number of crawlers per cm2 area. Ambri and Benoni were significantly more susceptible and supported a mean density of 55.66 and 58.00 scales/cm2, respectively. The mean scale population (53.76/cm2) recorded during October, 1987 declined to 10.23/cm2 in March, 1988.