Trimeresurus insularis or Indonesian pit viper, Lesser Sunda Islands pit viper, Sunda white-lipped pit viper, red-tailed pit viper is a venomous pit viper species found in eastern Java and the Lesser Sunda Islands, Indonesia.

Description

The scalation includes 21 rows of dorsal scales at midbody, 156–164/156–167 ventral scales in males/females, 70–75/54–59 subcaudal scales in males/females, and 7–12 supralabial scales. Their color patterns are often found to be green or a blue-green color with specific populations even containing yellow variants as well.

Geographic range

It is found in Indonesia on eastern Java, Adonara, Alor, Bali, Flores, Komodo, Lombok, Padar, Rinca, Romang, Roti, Sumba, Sumbawa, Timor, and Wetar and East Timor. The type locality given is "Soe, Timor". They are arboreal and can be found in dry monsoon forests at elevations up to 1200 m above sea level.