Imperfect chemical female mimicry in males of the ant Cardiocondyla obscurior
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Winged and wingless males coexist in the ant Cardiocondyla obscurior. Wingless (“ergatoid”) males never leave their maternal colony and fight remorselessly among each other for the access to emerging females. The peaceful winged males disperse after about 10 days, but beforehand also mate in the nest. In the first 5 days of their life, winged males perform a chemical female mimicry that protects them against attack and even makes them sexually attractive to ergatoid males. When older, the chemical profile of winged males no longer matches that of virgin females; nevertheless, they are still tolerated, which so far has been puzzling. Contrasting this general pattern, we have identified a single aberrant colony in which all winged males were attacked and killed by the ergatoid males. A comparative analysis of the morphology and chemical profile of these untypical attacked winged males and the tolerated males from several normal colonies revealed that normal old males are still performing some chemical mimicry to the virgin queens, though less perfect than in their young ages. The anomalous attacked winged males, on the other hand, had a very different odour to the females. Our study thus exemplifies that the analysis of rare malfunctioning can add valuable insight on functioning under normal conditions and allows the conclusion that older winged males from normal colonies of the ant C. obscurior are guarded through an imperfect chemical female mimicry, still close enough to protect against attacks by the wingless fighters yet dissimilar enough not to elicit their sexual interest.
KeywordsFemale mimicry Intraspecific chemical mimicry Alternative reproductive tactics Ant males
We thank the personnel of the Mass Spectrometry Centre of the University of Florence (C.I.S.M.) for gas chromatography–mass spectrometry, A. Schrempf for the experimental help, M. Sixt, A. Schrempf, S. Tragust and E.D. Morgan for the discussion and the editor and three anonymous referees for the constructive comments on the manuscript. This study was supported by the DFG (He 1623/23). Collecting colonies was allowed by Brazilian authorities (permit RMX 004/02), and the experiments comply with the current laws of Germany.
- Kugler J (1983) The males of Cardiocondyla emery (Hymenoptera: Formicidae) with the description of the winged male of Cardiocondyla wroughtoni (Forel). Isr J Entomol 17:1–21Google Scholar
- Turillazzi S, Sledge MF, Cremer S, Heinze J (2002) A method for analysing small-size specimens in GC–MS. Ins Soc Life 4:169–175Google Scholar