Sexual selection for symmetrical male medflies (Diptera : Tephritidae) confirmed in the field



Hunt MK, Nicholls CJ, Wood RJ, Rendon AP & Gilburn A (2004) Sexual selection for symmetrical male medflies (Diptera : Tephritidae) confirmed in the field. Biological Journal of the Linnean Society, 81 (3), pp. 347-355.

The role of fluctuating asymmetry as an indicator of fitness to females in mate choice remains controversial. Previous studies indicated that male medflies with symmetrical supra-fronto-orbital (SFO) bristles achieve relatively high mating success under laboratory conditions. Here we present data from field cage studies of wild collected medflies in Guatemala and Crete, which reveal the same association between fluctuating asymmetry in SFO bristle length and mating success as that seen in the laboratory. The experiments in Crete included males that were missing one or both of their bristles. A comparison of mating success between the three groups indicated that the mere presence of bristles did not exert a major influence. Analysis of attempted courtships suggests that the association between male mating success and FA in bristle length appears to be generated as a result of females being more likely to enter into courtships with symmetrical males, rather than through a rejection of asymmetrical males during or after it. This raises the possibility that the primary stimulus that makes a symmetrical male attractive is acting at too great a distance to depend on symmetry itself. Alternatives might include superior pheromone emissions or the occupation of a prime location within the lek.

Ceratitis capitata; fluctuating asymmetry; Mediterranean fruit fly; SFO bristles

Biological Journal of the Linnean Society: Volume 81, Issue 3

Publication date31/03/2004
Publication date online10/03/2004
PublisherWiley-Blackwell for the Linnean Society of London

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Dr Andre Gilburn

Dr Andre Gilburn

Senior Lecturer, Biological and Environmental Sciences