Ecological characteristics of a cave‐dwelling moth species, Triphosa dubitata (Lepidoptera: Geometridae), in Baram and Ssang caves in Gangwon Province, Korea

This study was performed to clarify the ecological characteristics of a cave‐dwelling moth species, Triphosa dubitata Linnaeus (Lepidoptera: Geometridae), at Baram cave and at Ssang cave within Pyeongchang‐gun of Gangwon province in south Korea. We investigated T. dubitata population for 3 days from March 2013 to October 2013 (except September) and in January 2014. We used a section investigation method in the caves every month to determine their ecological characteristic. A nocturnal investigation using a high intensity discharge lamp adjacent to the entrance of the cave was conducted in parallel with a diurnal investigation using butterfly traps to investigate the movement of T. dubitata. In order to investigate the range of habitat temperature of moths, we used a dual laser targeting infrared thermometer to measure the cave temperatures. We caught individuals of T. dubitata L.: 8,574 individuals in Baram cave and 828 individuals in Ssang cave. As 9,095 individuals (97 %) appeared at a temperature of −3°C ~ 8°C, it was verified that the adults were living at specific temperatures. In addition, T. dubitata adults were not active outside the caves; they entered the cave as soon as they developed from pupa into adults. These results showed that T. dubitata depended on food plants outside of the cave during the egg–larva–pupa stages, and they used the cave as a habitat for long‐term survival when they develop into adults.