About Castalius rosimon (Fabricius, 1775)
Castalius rosimon, commonly known as the common Pierrot, is a small butterfly belonging to the lycaenid (blues) family. It can be found across South and Southeast Asia. Its known distribution includes Sri Lanka, Bangladesh, India, Myanmar, and Tenasserim, with its range extending into the Malayan subregion. Within the Indonesian archipelago, this butterfly is present in northeastern Sumatra, Kalimantan, eastern Java, Bali, Bangka, Timor, Wetar, Kissar, Sumbawa, and Sulawesi. In India, it occurs south of the outer Himalayan ranges (with the exception of desert areas), as well as in east India, the northwest Himalayas, Assam, the Andaman Islands, and the southern Nicobar Islands. Two subspecies are recognized: the subspecies godarti Fruhstorfer, 1918 is found in the South Moluccas, while the subspecies monrosi Semper, 1887 occurs in the Philippines.
