Sperm reflux and its role in multiple mating in males of a butterfly Polygonia c-aureum Linnaeus (Lepidoptera : Nymphalidae)

The relationship between sperm quantity in the duplex and that in the vasa deferentia was examined in the Asian comma butterfly, Polygonia c-aureum. I n virgin males, the number of eupyrene sperm bundles in the duplex increase d linearly with age, whereas that in the vasa deferentia was consistently s mall. However, numerous sperm were found in the vasa deferentia of males im mediately after mating. The number of eupyrene sperm bundles in the vasa de ferentia after mating significantly increased with age and with increasing the time interval between matings. From these and other results, it was sug gested that some sperm in the duplex were moved back to the vasa deferentia during mating, and that such sperm reflux provides a means to save sperm f or multiple mating. (C) 1999 Elsevier Science Ltd. All rights reserved.