TY - JOUR
T1 - Male competition in Cardiocondyla ants
AU - Heinze, J.
AU - Hölldobler, B.
AU - Yamauchi, K.
N1 - Funding Information:
Acknowledgements Studies in Japan were supported in part by a Grant-in-Aid (No. 09044068) from the Japan Ministry of Education, Science and Culture. Laboratory studies in Würzburg and Erlangen were supported by the Deutsche Forschungsgemeinschaft (He 1623/ 7-1 and Heisenberg-grant He 1623/6-1). We are grateful to J.H.C. Delabie to provide a permission to collect ants on the property of CEPLAC and to M. Obermayer and S. Trenkle for histology.
PY - 1998/4
Y1 - 1998/4
N2 - The two types of males in the ant genus Cardiocondyla differ remarkably in morphology and behavior. Ergatoid males are wingless fighters whose spermatogenesis continues throughout their entire adult lives and which therefore have an 'unlimited' sperm supply. They attempt to kill all eclosing ergatoid rivals and thus to increase their share in copulations with the virgin queens reared in their nests. Winged males, on the other hand, are docile and emigrate from the nests a few days after eclosion, probably to mate with queens from other colonies. By this time, their testes have fully degenerated and all sperm is stored in the seminal vesicles. Before emigration, winged males may mate with virgin queens in their maternal nests, but they are nevertheless rarely attacked by ergatoid males. In the laboratory, the life expectancy of ergatoid males is only slightly higher than that of winged males, but because of the emigration of the latter the difference is likely to be more pronounced in the field. Both male morphs are capable of inseminating more than 35 virgin queens. However, winged males older than 14 days mate less often than ergatoid males of similar age, probably due to sperm depletion in later life. The spermathecae of queens inseminated by ergatoid males contained significantly more sperm than those of queens which mated with winged males. We discuss the evolution of intranidal mating and male polymorphism in ants.
AB - The two types of males in the ant genus Cardiocondyla differ remarkably in morphology and behavior. Ergatoid males are wingless fighters whose spermatogenesis continues throughout their entire adult lives and which therefore have an 'unlimited' sperm supply. They attempt to kill all eclosing ergatoid rivals and thus to increase their share in copulations with the virgin queens reared in their nests. Winged males, on the other hand, are docile and emigrate from the nests a few days after eclosion, probably to mate with queens from other colonies. By this time, their testes have fully degenerated and all sperm is stored in the seminal vesicles. Before emigration, winged males may mate with virgin queens in their maternal nests, but they are nevertheless rarely attacked by ergatoid males. In the laboratory, the life expectancy of ergatoid males is only slightly higher than that of winged males, but because of the emigration of the latter the difference is likely to be more pronounced in the field. Both male morphs are capable of inseminating more than 35 virgin queens. However, winged males older than 14 days mate less often than ergatoid males of similar age, probably due to sperm depletion in later life. The spermathecae of queens inseminated by ergatoid males contained significantly more sperm than those of queens which mated with winged males. We discuss the evolution of intranidal mating and male polymorphism in ants.
KW - Alternative behaviors
KW - Intranidal mating
KW - Polymorphism
KW - Reproductive tactics
KW - Spermatogenesis
UR - http://www.scopus.com/inward/record.url?scp=2642616237&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=2642616237&partnerID=8YFLogxK
U2 - 10.1007/s002650050435
DO - 10.1007/s002650050435
M3 - Article
AN - SCOPUS:2642616237
SN - 0340-5443
VL - 42
SP - 239
EP - 246
JO - Behavioral Ecology and Sociobiology
JF - Behavioral Ecology and Sociobiology
IS - 4
ER -