Lamproptera meges decius (Green Dragontail)
 
Lamproptera meges, the green dragontail, is a species of swallowtail butterfly (family Papilionidae) found in parts of South Asia and Southeast Asia. There are ten subspecies. A specimen from Java is the type species of the genus. A small butterfly, the green dragontail has a wingspan of 40 to 55 millimetres (1.6 to 2.2 in). It is basically black and white in colour scheme, it has a very large white-tipped tail, 25 to 40 millimetres (0.98 to 1.57 in) long. The forewing has a triangular hyaline (glass-like) patch with black borders, and thin black stripes along the veins, forming six to eight spot/bands. It also has a pale band running obliquely across the pre-discal area. This band is continued onto the black hindwing which bears the long tail and prominent abdominal wing fold. In this species, the pale bands are light green while in its closely related species, Lamproptera curius, they are white. Also in L. curius, the white band has a hyaline outer edge. Sexes are alike, but the female is duller and has a ventral copulation groove before the tip of the abdomen. The males of this species do not have the sex mark (scent organ) found in L. curius.The butterfly is found in northeastern India, in the states of Assam, Arunachal Pradesh, Manipur and Nagaland. It is also found in Myanmar, Thailand, Laos, Vietnam, southern China (including Hainan), Cambodia, peninsular and eastern Malaysia, the Indonesian archipelago, Brunei, and the Philippines. In Indonesia, it is found on the islands of Sulawesi, Kalimantan, Nias, Bangka and Java. In 2006, it was reported from Zhangjiajie of Hunan Province. The Dragontails ( Lamproptera ) are among the most delightful and entertaining butterflies in the Oriental region, being much smaller in size than other Papilionidae, and unique among them in having completely transparent "windows" in the forewings, and very long tails on the hindwings.
They are members of the Leptocircini, a tribe which also includes the Oriental genera Graphium and Pathysa, the neotropical genera Protesilaus and Eurytides, and the European Scarce Swallowtail Iphiclides podalirius.
There are only 2 species in the genus Lamproptera, i.e. meges and curius, both of which are found in Assam, Myanmar, Thailand, Laos, Vietnam, southern China, the Philippines, peninsular Malaysia and Borneo. The range of meges extends further south and east, to include Sulawesi and Java.
Lamproptera meges is the commoner of the 2 species. It is known as the Green Dragontail because the upperside hindwing has a pale green band, and the butterfly has a distinct greenish hue when seen in flight. The other species curius is rarer and has a white band on the upperside hindwing. Also, unlike meges, it has a tuft of long white androconial scales in the dorsal fold of the upperside hindwings.
Habitats
Lamproptera meges breeds in wet tropical and subtropical rainforests at altitudes between about 100-1000m. It is always found in association with rivers, streams or waterfalls.