title: Cooperative nest building and brood care by nestmates and non nestmates in Ropalidia marginata : implications for the evolution of eusociality.
abstract: In the primitively eusocial wasp, Ropalidia marginata, low levels of intra-colony genetic relatedness, lack of intra-colony kin discrimination and acceptance of young wasps into alien colonies, prompted us to investigate whether or not there exists a cost of such high genetic variability. Freshly eclosed wasps were paired either with their nestmates or with their non nestmates and their performance in nest building and brood care were compared. There was no demonstrable difference between nestmate and non nestmate pairs in terms of success in raising adult offspring, time required for nest initiation, brood developmental period and productivity. There was also no difference in the efficiency of cooperation and division of labour between the nestmate pairs and non nestmate pairs. These results reinforce the idea that the haplodiploidy hypothesis is insufficient to explain the prevalence of worker behaviour in R. marginata and emphasize the importance of factors other than genetic relatedness in the evolution of eusociality.
authors.affiliation: Centre for Ecological Sciences, Indian Institute of Science, Bangalore 560 012, India, , , , , , IN.
authors.forename: H S
authors.initials: HS
authors.lastname: Arathi
authors.affiliation: Behavioural Ecology Laboratory, Animal Behaviour Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bangalore 560 064, India, , , , , , IN.
authors.forename: Raghavendra
authors.initials: R
authors.lastname: Gadagkar
keywords: Cooperation; Eusociality; Genetic variability; Key words Primitively eusocial wasps; Ropalidia marginata