The third and final volume in this series devoted to insects in Nepal covers 3,131 species of insects in the orders Hemiptera, Hymenoptera, Coleoptera and Diptera. Another 63 species in the order Odonata have been appended as well, bringing the number of insect fauna in Nepal to 5,175 species. The text of this inventory follows the sequence of natural orders; super family, form, sub-form, and tribe are arranged alphabetically. Each of the orders is briefly described to capture the diagnostic features of the insects. It is hoped that this work will facilitate or initiate future contributions to the science of insect taxonomy, nomenclature and ecology of this very important group of living organisms.