An investigation on the immature biology of butterflies on Orchid Island (Lanyu in Chinese), Taiwan was carried out while executing a monitoring program on the effects of exotic, invasive species to this small island. Immatures of Nacaduba berenice leei, a recently discovered lycaenid, were found during the investigation. The recognized larval host is Rourea minor of the Connaraceae, a plant family previously unknown as a host for populations of N. berenice from the other regions.