Post‐mounting courtship and the neutralizing of male competitors through “homosexual” mountings in the fly Hydromyza livens F. (Diptera: Scatophagidae)

Abstract

Post‐mounting courtship behaviour of a 6–8 mm long scatophagid fly Hydromyza livens which lays its eggs in yellow water lily (Nuphar lutea) is described and analysed. Enigmatic male–male encounters are described, along with lengthy “homosexual” mounting behaviour. A possible interpretation of both types of behaviour is given, with reference to their adaptive significance and the special problems encountered by males in locating females.

Keywords:

• Behaviour
• courtship
• Diptera
• homosexual
• post‐mounting
• Scatophagidae
• water lily

Acknowledgements

I should like to thank Professor John Alcock of Arizona State University for reading through the initial draft and making many helpful comments. Dr John Ismay of the University Museum, Oxford kindly identified the fly for me and also read through the draft version of the text.