Scoliopteryx libatrix (Noctuidae) and Triphosa haesitata (Geometridae) in caves in Manitoba, Canada

The trogloxene moths Scoliopteryx libatrix and Triphosa haesitata found in small caves in Manitoba, Canada, were studied over a two year period. Fewer individuals of the latter species were found (126:54), but both species overwintered in caves in which the temperature remained above freezing. Triphosa haesitata tended to seek sites further from the cave entrance and preferred slightly warmer air temperature and greater relative humidity than S. libatrix . These findings may be related to the fact that T. haesitata is near the northern limit of its range. Noteworthy was the finding that some specimens (about 10%) of both species remained in the caves throughout the year. These may represent a portion of the population that spends a second concurrent winter underground prior to leaving the caves the following spring. In the laboratory, at cave temperature (5 degree C), adult S. libatrix remained viable up to 14 months after capture.