The Common Gull Butterfly, scientifically known as Cepora Nerissa, is a charming small to medium-sized butterfly belonging to the Pieridae family. Native to India and Southeast Asia, including Nepal, this species thrives in the northwestern Himalayas at elevations of up to 4,000 feet (1,200 m). It primarily inhabits drier plains, cultivated farmlands, and scrub forests and exhibits a fascinating seasonal dimorphism. These butterflies are darker and slightly larger during the wet season than their dry-season counterparts.
These nimble creatures fly close to the ground at a reasonable speed following a zigzag path. After lengthy flights, they like to rest on leaves and bushes. Their diet mainly consists of flowers from Tridax procumbens, Sida rhombifolia, Alternanthera, and Lantana plants.
On hot days, you can observe Common Gull Butterflies mud puddling - that is drinking moisture from the sand. When they're not busy drinking or flying about, they prefer perching atop bushes with wings closed. These social butterflies often settle in large groups and participate in massive migrations. You can frequently find them in the company of Yellow and White Orange Tips, Pioneers, and Striped Albatrosses—all sharing the same habitat. They quickly greet the morning sun by opening their wings before getting busy with their day.
These butterflies don't linger too long on one flower; they always seem in a hurry to get to the next bloom. Males are known for their habit of visiting mud patches and sandy beds in large groups during migratory flights. Common Gull Butterflies are quite abundant in dry scrublands where their larval food plants thrive. They can be found dispersed across various elevations during migrations, even though they don't breed there.
The life cycle of the Common Gull Butterfly begins with a female laying her eggs on the underside of the leaves of a host plant, like a Capparis species. The initially yellow, small oval-shaped eggs eventually hatch into green caterpillars with black markings. These caterpillars feed on the leaves of their host plant, growing up to 4 cm before pupation. After several weeks, they form brown pupae attached to leaves or shoots with silk. Eventually, adult butterflies emerge from the pupae; they are white with black markings and have a wingspan of 40 to 65 mm.
Male butterflies display a grayish-blue hue at the base of their white wings and along their wing veins. The forewing has a creamy white color with black veins, while the hind wing is covered with yellow and bordered by diffuse black veins. On the underside of their wings are various dusky black and yellow patterns.
Female butterflies closely resemble males but are darker in color. Their wings have more extensive black vein borders and less white in specific regions. The underside appears similar to males but boasts broader veins and females have slightly more rounded forewings.
Common Gull Butterflies can be found in Nepal's Terai region and hilly areas. Spring and summer are the best time to catch a glimpse of these lovely creatures when they are most active.