The life histories of three species of Corydalidae (Megaloptera) from Japan

Abstract

The life histories of three species of Corydalidae (Megaloptera) from Japan are explored, focusing on their larval climbing locations, climbing and emergence conditions and then adult emergence behaviours. At the Sugihara River site in Hyogo Prefecture, Parachauliodes continentalis final-instar larvae climbed much earlier than those of Protohermes grandis. Parachauliodes continentalis adults emerged earlier and for a shorter period than Pr. grandis adults. In the two corydalid species, adults of both sexes emerged at the same time. Parachauliodes japonicus males emerged slightly before the females at the Hokkesan-tani River site in Hyogo Prefecture, and so have a unique mating behaviour. Almost all larvae of the three species climbed at night during or following a rainy day, when the ground was wet. This behaviour is thought to be an adaptation that allows the larvae to avoid desiccation while making it easier to excavate the pupal chamber in wet soil.

Keywords:

• Corydalidae
• fence trap
• pitfall trap
• climbing
• pupation
• emergence

Acknowledgements

I am grateful to Dr Elwin Evans of Michigan State University for reviewing this manuscript and contributing helpful comments. I also thank Dr Fumio Hayashi of Tokyo Metropolitan University, Dr Takuzo Yamada of Nagoya Art University, Mr Koji Iizuka, Mr Ryohei Miyai of Tokyo, Dr Stanley K. Sessions of Hartwick College, and Dr John Applegarth of Oregon SSAR for providing information useful for this study.