Ecological Aspects of Pear Psyllid, Cacopsylla pyricola (Hemiptera: Psyllidae), and Its Associated Natural Enemies, as A new Pest on Pear Trees in Egypt. - Youssef, A. S.; Nadia Aly, A.; Abd-Rabou, Shaaban (Egyptian Academic Journal of Biological Sciences. A, Entomology, 2015)