1. POPULATION DYNAMICS OF EUPHYLLURA OLIVINA COSTA, 1857 (PSYLLIDAE: HEMIPTERA) IN OLIVE TREES IN THE SEMI-ARID REGION OF DJELFA (ALGERIA). Authors: NASSIMA CHAABANE, SMAIL CHAFAA, FRAH NAAMA, YASSINE NOUIDJEM, FATEH MIMECHE.2. DIVERSITY OF ARTHROPODS SUBSERVIENT TO OLIVE GROVES IN ARID REGION (NORTHEASTERN ALGERIA). Authors: HAYET MIMECHE, SMAIL CHAFAA, AYACHE LAABASSI.