Thisbook is an introduction to the systematics and the evaluation of the richness of the entomofauna of the Djurdjura Kabylia. The book mainly discusses the differences between the richness encountered on two agricultural orchards (monoculture of onion Allium cepa L.). One of the orchards (Illoula-Oumalou region) is organic and the second (Ain-Zaouia) receives fertilizers and pesticides every year. A total of 145 species of arthropods divided into 77 families, 16 orders have been reported in this guide. The work shows that although the organic orchard is too small, it has a very high richness compared to the orchard treated with pesticides and fertilizers. The region of Illoula-Oumalou is rich in Hymenoptera, on the other hand the region of Ain-Zaouia is rich in Gastropoda.