Maintenance of biodiversity within an agro ecosystem is necessary to ensure the continued supply of goods and services such as: (i)evolution and crop and livestock improvement through breeding; (ii)biological support to production -provided by the organisms that make up the biological diversity of the agro ecosystem and (iii)wider ecological functions - valuable ecological processes that result from the interactions between species and between species and the environment include the maintenance of soil fertility, water quality and climate regulation this work aims at aims at a synthesis of available knowledge of litter ecosystem in agricultural farms, from the viewpoint of the sustainability of entomological resources at various ,levels, laying stress on their biological diversity with emphasis on their functional divers t' Ai a time when we are losing natural forests at a fast rate through conversion of forest into cultivated land, the thoughts of dwindling biodiversity through lack of litter become predominant. Contents: introduction; insect Morphology; Digestive System: Senses and Communication; Endocrine System; Evolution of Insects : Types c' Insects; Insect Defenses.