“Riding” behaviour by males of Conops quadrifasciata (Diptera: Conopidae): Do females set up “riders” as targets for takeovers by larger males?

Abstract

Males of Conops quadrifasciata “claim” females in late morning and then spend the rest of the day exposed as “riders” to attacks by other males. Male riders can respond to an attack by performing an abdomen‐lift which denies the attacker access to the female's genitalia. Attacking males can tailor their behaviour to suit the prevailing conditions. If a rider is engaged in a “repeat” copulation (as he does at regular intervals), the attacker “waits” beside the rider. If the rider is not in genitalic contact with the female, the attacker tries to mate with her immediately. It is proposed that females deliberately expose their riders to takeovers in order to gain the fittest mate.

Keywords:

• Conopidae
• Diptera
• flies
• mating behaviour
• post‐copulatory guarding
• riders

Acknowledgements

I should like to thank Professor John Alcock of Arizona State University for reading through the initial draft and making many helpful comments. Similar thanks are due to Dr John Ismay of the University Museum, Oxford, and two anonymous reviewers.