@article {3809, title = {Mating success and potential male-worker conflict in a male-dimorphic ant}, journal = {BMC Evolutionary Biology}, volume = {7:114}, year = {2007}, note = {Part of FORMIS 08; from-DPW, }, month = {10 July 2007}, pages = {8 p.}, abstract = {*[When the survival probability of males is taken into account, docile winged males are more likely to mate multiply and in consequence have a higher estimated average mating success than aggressive ergatoid males. Therefore, male larvae are expected to prefer developing into winged instead of ergatoid adults. Though male larvae can expect a higher average mating success when developing into winged males, most colonies produce only ergatoid males under standard conditions.]}, author = {Schrempf, A. and Darrouzet, E. and Heinze, J.} } @article {3720, title = {Stealthy invaders: the biology of Cardiocondyla tramp ants}, journal = {Insectes Sociaux}, volume = {53}, year = {2006}, note = {Part of FORMIS 07; from-DPW, }, pages = {1-7}, abstract = {*[We document that the life history of Cardiocondyla closely resembles that of the more conspicuous tramp species, with polygyny, intranidal mating, budding,worker sterility, low genetic variability, \& possibly also unicoloniality. Given that introduced Cardiocondyla may locally reach a very high population density, the effects of these stealthy invaders on the native arthropod fauna should receive more attention.]}, author = {Heinze, J. and Cremer, S. and Eckl, N. and Schrempf, A.} } @article {3721, title = {Population structure of the male-polymorphic ant Cardiocondyla obscurior}, journal = {Studies on Neotropical Fauna and Environment}, volume = {40}, year = {2005}, note = {Part of FORMIS 07; from-DPW, }, pages = {187-190}, abstract = {*[Males of the myrmicine ant Cardiocondyla obscurior Wheeler are either wingless, ergatoid fighters, or winged, peaceful dispersers. Collection, of 124 colonies from Bahia, Brazil, between January 2003 \& January 2004, revealed that ergatoid males \& a few female sexuals were produced throughout the year. Female sexual production peaked in April 2003, \& was followed by a significant decline in colony size, presumably due to colony fragmentation or budding. Not a single winged male was found, suggesting that in this population, they are indeed reared only under particularly stressful conditions, as previously observed in the laboratory.]}, author = {Heinze, J. and Delabie, J.H.C.} } @article {3722, title = {Fighting for a harem of queens: physiology of reproduction in Cardiocondyla male ants}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {90}, year = {1993}, note = {Part of FORMIS 95; from NAL{\textquoteright}S AGRICOLA; verified-DPW; from ANTBIB; verified-PSW.}, month = {Published: Sep 1}, pages = {8412-8414}, abstract = {Several species of the ant genus Cardiocondyla produce dimorphic males, which exhibit sharply different mating strategies. Winged males typically disperse to mate outside the nest, whereas wingless, ergatoid males stay in the nest and aggressively employ their mandibles against competing ergatoid males to monopolize the virgin queens eclosing in the nest. Such aggressive mating strategy would only be adaptive if the males had unlimited sperm supply. Histological studies showed that, contrary to the rule in the Hymenoptera order, the ergatoid Cardiocondyla males are indeed able to produce sperm during their entire adult life. Winged males, on the other hand, have only a limited sperm supply since spermatogenesis ceases in the late pupal stage.}, author = {Heinze, J. and H{\"o}lldobler, B.} } @article {3723, title = {Behavior of ergatoid males in the ant, Cardiocondyla nuda}, journal = {Insectes Sociaux}, volume = {40}, year = {1993}, note = {Part of FORMIS 95; from ANTBIB; verified-PSW; from-DPW, }, month = {September 1993}, pages = {273-282}, abstract = {*[Cardiocondyla nuda ergatoid males attack \& frequently kill young males, during or shortly after eclosion. Therefore, smaller colonies contain typically only one adult male, which may inseminate all alate queens, which are reared in the colony over a few weeks. However, in larger colonies, several males may be present, fighting among adult males was not observed.]}, author = {Heinze, J. and K{\"u}hnholz, S. and Schilder, K. and H{\"o}lldobler, B.} } @article {3724, title = {Male polymorphism and gynandromorphs in the ant Cardiocondyla emeryi}, journal = {Naturwissenschaften}, volume = {84}, year = {1997}, note = {Part of FORMIS 00; from PSW; from-DPW, }, month = {Published: Mar 1}, pages = {129-131}, author = {Heinze, J. and Trenkle, S.} } @article {3709, title = {Male fighting and "territoriality" within colonies of the ant Cardiocondyla venustula}, journal = {Naturwissenschaften}, volume = {96}, year = {2009}, note = {Part of FORMIS 09; from-DPW, }, month = {January, Publish}, pages = {159-163}, abstract = {*[The ant genus Cardiocondyla is characterized by a bizarre male polymorphism with wingless fighter males \& winged disperser males. Winged males have been lost convergently in several clades, \& in at least one of them, wingless males have evolved mutual tolerance. To better understand the evolutionary pathways of reproductive tactics, we investigated Cardiocondyla venustula, a species, which in a phylogenetic analysis clusters with species with fighting \& species with mutually tolerant, wingless males. Wingless males of C. venustula use their strong mandibles to kill freshly eclosed rival males \& also engage in short fights with other adult males, but in addition show a novel behavior hitherto not reported from social insect males: they spread out in the natal nest \& defend territories against other males. Ant males therefore show a much larger variety of reproductive tactics than previously assumed.]}, author = {Frohschammer, S. and Heinze, J.} } @article {3710, title = {A heritable component in sex ratio and caste determination in a Cardiocondyla ant}, journal = {Frontiers in Zoology}, volume = {6: 27}, year = {2009}, note = {Part of FORMIS 10; from-DPW, }, month = {Published: 28 Oc}, pages = {6 p.}, abstract = {*[Studies on sex ratios in social insects provide among the most compelling evidence for the importance of kin selection in social evolution. The elegant synthesis of Fisher{\textquoteright}s sex ratio principle and Hamilton{\textquoteright}s inclusive fitness theory predicts that colony-level sex ratios vary with the colonies{\textquoteright} social and genetic structures. Numerous empirical studies in ants, bees, and wasps have corroborated these predictions. However, the evolutionary optimization of sex ratios requires genetic variation, but one fundamental determinant of sex ratios - the propensity of female larvae to develop into young queens or workers ("queen bias") - is thought to be largely controlled by the environment. Evidence for a genetic influence on sex ratio and queen bias is as yet restricted to a few taxa, in particular hybrids. Because of the very short lifetime of their queens, ants of the genus Cardiocondyla are ideal model systems for the study of complete lifetime reproductive success, queen bias, and sex ratios. We found that lifetime sex ratios of the ant Cardiocondyla kagutsuchi have a heritable component. In experimental single-queen colonies, 22 queens from a genetic lineage with a highly female-biased sex ratio produced significantly more female-biased offspring sex ratios than 16 queens from a lineage with a more male-biased sex ratio (median 91.5\% vs. 58.5\% female sexuals). Sex ratio variation resulted from different likelihood of female larvae developing into sexuals (median 50\% vs. 22.6\% female sexuals) even when uniformly nursed by workers from another colony. Consistent differences in lifetime sex ratios and queen bias among queens of C. kagutsuchi suggest that heritable, genetic or maternal effects strongly affect caste determination. Such variation might provide the basis for adaptive evolution of queen and worker strategies, though it momentarily constrains the power of workers and queens to optimize caste ratios.]}, author = {Frohschammer, S. and Heinze, J.} } @article {3718, title = {Male polymorphism in the ant Cardiocondyla minutior (Hymenoptera: Formicidae)}, journal = {Entomologia Generalis}, volume = {23}, year = {1999}, note = {Part of FORMIS 99; from Heinze; from NAL{\textquoteright}S AGRICOLA; from-DPW, }, pages = {251-258}, abstract = {Males of the myrmicine ant Cardiocondyla minutior may be either winged and similar to normal ant males in morphology and behavior, or aggressive, wingless and workerlike in external appearence ("ergatoid"). Compared to other ant males, spermatogenesis appears to be prolonged in both male morphs, though the testes had completely degenerated in winged males 20d after eclosion. A comparative investigation supports the hypothesis that only ergatoid males are produced in those Cardiocondyla species that have on average large colony sizes, whereas both male morphs co-occur in species with small colony size.}, author = {Heinze, J.} } @article {3719, title = {Production of winged and wingless males in the ant Cardiocondyla minutior}, journal = {Insectes Sociaux}, volume = {52}, year = {2004}, note = {Part of FORMIS 06; from-DPW, }, pages = {275-278}, abstract = {*[Six large stock colonies from Tobago \& 4 large stock coloniesfrom Bahia, Brazil were used as sources to set up experimental subcolonies. Wingless (= ergatoid) males of the tramp ant Cardiocondyla minutior attack \& kill their young ergatoid rivals, thus attempting to monopolize mating with female sexuals reared in the colony. Because of the different strength of local mate competition in colonies with one or several reproductive queens, we expected the production of new ergatoid males to vary with queen number. Sex ratios were mostly female-biased, but neither the percentage of ergatoid males nor of female sexuals among the first 20 sexuals produced varied considerably with queen number. Experimental colony fragmentation led to the production of winged males, while in unfragmented control colonies only ergatoid males eclosed.]}, author = {Heinze, J. and B{\"o}ttcher, A. and Cremer, S.} } @article {3670, title = {Imperfect chemical female mimicry in males of the ant Cardiocondyla obscurior}, journal = {Naturwissenschaften}, volume = {95}, year = {2008}, note = {Part of FORMIS 08; from NAL{\textquoteright}S AGRICOLA; from-DPW, }, month = {Nov, Published o}, pages = {1101-1105}, abstract = {

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 odor 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.

}, author = {Cremer, S. and D{\textquoteright}Ettorre, P. and Drijfhout, F.P. and Sledge, M.F. and Turillazzi, S. and Heinze, J.} }