Ahmad, K.F., Shah, W.H., Khalid, M., & Samina, J. 2004 Distribution of San Jose scale, Quadraspidiotus perniciosus (Com.) [Diaspididae: Homoptera] on apple trees in Kashmir, Pakistan.. Sarhad Journal of Agriculture 20(1): 135-142.

Notes: Studies on the spatial and temporal distribution of San Jose scale (SJS), Q. perniciosus [Diaspidiotus perniciosus], on apple trees were carried out in three apple growing localities, i.e. Bagh, Muzaffarabad and Rawalakot, in Kashmir, Pakistan, during 1999. The SJS population, by examining a total of 1152 samples (i.e. 6 trees x 6 samples x 2 sites x 16 sampling time) per locality varied significantly (P<0.001) throughout the sampling period. It also significantly (P<0.001) varied on different cultivars of apple at different localities and sites. The apple orchard at Dheerkot (Bagh) locality was found severely infested compared to two other localities at Lamniyan (Muzaffarabad) and Rawalakot. The intra-tree variation was also evident at different localities. The data indicates that all the indigenous and introduced cultivars of apple were found infested by SJS with varying degrees of susceptibility. Among local cultivars, Banky was comparatively the least infested whereas the introduced cultivar (Star-Crimson) was found highly susceptible to SJS infestation. The pest population was significantly high at the upper half of the canopy compared to the lower half.