Acanthoscelides Schilsky is the large genus of Neotropical bruchid beetles, in which most species show host plant specialization. The species of A. obtectus Say specialized on Phaseolus beans and therefore considered pests. Six legume grain species (Dried common bean, green common bean, lentil, cowpea, broad bean, and soybean) were selected to study the biology of this insect pest on these different legumes under the prevailing environmental conditions of 25 ± 2°C and 60 ± 10% RH. The results showed that an average number of eggs per mated female (fecundity) was recorded in common bean dried and green (26.33 and 22.66 eggs). While the fecundity decreased significantly to 10.00, 9.66 and 4.00 eggs/ female at Soybean, Broad bean and Lentil, respectively. The results also showed that there was a significant difference (p<0.05) in the percentage of emerged adults among the different legume hosts, namely dried common bean and Cowpea the highest value (88.00 and 76.65%) and lowest percentage (17.97%) of emerged adults in green common bean respectively, while no adults emerged in Soybean, Broad bean and Lentil hosts and the developmental periods of A. obtectus on different legume hosts and mean periods varies depending upon the different hosts.