Results indicated that the Egyptian clover harbored 13, 8 and 6 species of pests, beneficial and visitor insects, belong to 22 families and 8 orders at Kafr EI-Sheikh, Egypt. Alfalfa was found to harbor 14, 11 and 5 species in 26 families belong to 11 orders. Diversity indices as meas­ured for each species and summed in relation to crop system were 2.28 and 3.10 for the clover and alfalfa at Kafr EI-Sheikh and Sebha, respec­tively. The relative abundance of species in each crop system had an ef­fect on diversity index values. In clover, Hypera brunneipennis (Boh.), Paederus alfierii (Koch.) and Apis militate L. were the dominant species at Kafr EI-Sheikh. Each insect population represented by 80.90. 85.32 and 65.62% of pests, beneficial and visitor insects, respectively. In alfal­fa, aphids (different species) and Coccinella spp. accounted for 48.56 and 80.82% for pests and beneficial species, respectively, at Sebha. It could be stated that each crop has dominant and subdominant species which differently affected population diversity.