The common name of State Butterfly of Tripura is ____.

Each Indian state may officially notify a set of state symbols — such as a state animal, bird, tree, and butterfly — to highlight species of ecological or cultural importance to that region and encourage awareness of their conservation.

In August 2019, acting on a recommendation of the Tripura State Board for Wildlife, the Tripura Government notified the Common Birdwing (Troides helena) as the State Butterfly of Tripura. It is one of the largest butterflies recorded in India and inhabits the forested tracts of North-East India, making it representative of the state's rich biodiversity.

• Common Silverline (Spindasis vulcanus) is a small lycaenid butterfly with metallic silver streaks on its underwings, common across the plains and scrublands of mainland India.

• Common Lascar (Pantoporia hordonia) is a nymphalid butterfly with dark-brown wings crossed by orange-and-white bands, seen along forest edges and gardens across South and Southeast Asia.

• Common Evening-Brown (Melanitis leda) is a satyrine butterfly with brown wings marked by prominent eye-spots, active mainly at dusk in shaded, grassy habitats across India.

None of these three carries an official state designation, which makes Common Birdwing the correct answer.