Olfactory systems of different species show variations in structure and physiology despite some conserved features. We characterized the olfactory circuit of the grasshopper Hieroglyphus banian of family Acrididae (subfamily: Hemiacridinae) and compared it to a well-studied species of locust, Schistocerca americana (subfamily: Cyrtacanthacridinae), also belonging to family Acrididae. We used in vivo electrophysiological, immunohistochemical, and anatomical (bulk tract tracing) methods to elucidate the olfactory pathway from the second-order neurons in antennal lobe to the fourth-order neurons in β-lobe of H. banian. We observe conserved anatomical and physiological characteristics through the fourth-order neurons in the olfactory circuit of H. banian and S. americana, though they are evolutionarily divergent (~ 57 million years ago). However, we found one major difference between the two species-there are four antennal lobe tracts in H. banian, while only one is reported in S. americana. Besides, we have discovered a new class of bilateral neurons which respond weakly to olfactory stimuli, even though they innervate densely downstream of Kenyon cells.