Cooperative nest building and brood care by nestmates and non nestmates in Ropalidia marginata  : implications for the evolution of eusociality (original) (raw)

Cooperative nest building and brood care by nestmates and non nestmates in Ropalidia marginata : implications for the evolution of eusociality

Oecologia, 1998

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 dierence between nestmate and non nestmate pairs in terms of success in raising adult ospring, time required for nest initiation, brood developmental period and productivity. There was also no dierence in the eciency of cooperation and division of labour between the nestmate pairs and non nestmate pairs. These results reinforce the idea that the haplodiploidy hypothesis is insucient 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.

Social organization in experimentally assembled colonies of Ropalidia marginata : comparison of introduced and natal wasps

Insectes Sociaux, 1997

In the primitively eusocial wasp, Ropalidia marginata worker behaviour cannot be explained satisfactorily by the haplodiploidy hypothesis due to the existence of polyandry, serial polygyny and movement of wasps between nests, which reduce intra-colony genetic relatedness to levels lower than the value expected between a solitary foundress and her offspring. We introduced wasps eclosing from one set of colonies into other colonies separated by a distance of 10 km or more, to examine the possibility of kin recognition and task specialization under conditions of low intracolony relatedness. Introduced wasps were readily accepted into unrelated foster colonies, where they performed most of the behaviours and tasks shown by the natal wasps. We found no evidence of kin recognition or task specialization among natal and introduced wasps. Introduced wasps sometimes became replacement queens in spite of the presence of natal wasps. Taken together with previous observations, these results lend support to the idea that factors other than genetic relatedness must play a prominent role in the evolution of worker behaviour in Ropalidia marginata.

Emergence of cooperation and division of labor in the primitively eusocial wasp Ropalidia marginata

Proceedings of the National Academy of Sciences, USA, 2018

In most primitively eusocial wasps new nests are initiated by a single female or by small groups of females. To study the emergence of division of labor (DOL) among the nest foundresses and to determine its possible effect on nest productivity we maintained newly eclosed females of Ropalidia marginata in small boxes with one, two, or three nestmate wasps of the same age per box. Only one wasp developed her ovaries and laid eggs in each box, while the other wasp(s) built the nest, brought food, and fed larvae, demonstrating the spontaneous emergence of reproductive DOL in the presence of more than one wasp. In nests with three wasps there was also a strong negative correlation between intranidal and extranidal work performed by the two nonreproductive workers, suggesting the spontaneous emergence of nonreproductive DOL; such nonreproductive DOL was absent in nestswith two wasps. Both reproductive and nonreproductive DOL were modulated by dominance behavior (DB). In nests with two wasps the egg layer showed significantly more DB than the non-egg layer before nest initiation; in nests with three wasps queens showed significantly more DB than intranidal workers, which in turn showed significantly more DB than extranidal workers. Productivities of nests (as measured by total brood on the day of eclosion of the first adult) initiated by one or two wasps were not different from each other but were significantly lower than that of three wasps. Thus, nonreproductive DOL, and not merely reproductive DOL, is necessary for increase in productivity.

Queen success is correlated with worker-brood genetic relatedness in a primitively eusocial wasp (Ropalidia marginata)

Experientia, 1993

Ropalidia marginata is a primitively eusocial polistine wasp in which, although there is only one queen at any given time, frequent queen replacements lead to a system of serial polygyny. One of the most striking features of this system is the enormous variation in the success of different queens. Measuring queen success as queen tenure, total number of offspring produced, number of offspring produced per day of tenure, and proportion of eggs laid that develop into adults, we show here that each measure of queen success is correlated with worker-brood genetic relatedness and not correlated with worker:brood ratio or the age of the queen at takeover. We interpret these results as meaning that queens are better able to obtain the cooperation of workers when worker-brood genetic relatedness is high.

The mechanism of nestmate discrimination in the tropical social wasp Ropalidia marginata and its implications for the evolution of sociality

Behavioral Ecology and Sociobiology, 1988

We have demonstrated that females of widespread phenomenon. The ability to discrimithe primitively eusocial tropical wasp Ropalidia nate kin from non-kin has been reported in marine marginata can discriminate nestmates from non-invertebrates, subsocial arthropods, sweat bees, nestmates outside the context of their nests. This honey bees, several species of ants and wasps, was accomplished by recording all behavioural in-fishes, frogs, toads, iguanas, birds and a variety teractions in a neutral arena and comparing toler-of mammals (reviews in Fletcher and Michener ance levels. In order for these wasps to make such 1986; Gadagkar 1985b; Gamboa et al. 1986a; a discrimination, howeyer, it was essential that Hepper 1986; Holldobler and Michener 1980; Linafter eclosion both the discriminated and the dis-senmair 1985; Sherman and Holmes 1985; Waldcriminating animals were exposed to their respec-man 1987); for the iguana see Werner et al. ; tive natal nests and nestmates. The results suggest for the fish see Quinn and Busack (1985); for the that both recognition labels and templates are ac-marine invertebrates see Grosberg and Quinn quired by the animals from sources outside their (1986) and Keough (1984). body, perhaps from their nest or nestmates. It is

Origin and evolution of eusociality: A perspective from studying primitively eusocial wasps

Journal of Genetics, 1990

Eusocial insects are those that show overlap of generations, cooperative brood care and reproductive caste differentiation. Of these, primitively eusocial insects show no morphological differences between reproductive and worker castes and exhibit considerable flexibility in the social roles that adult females may adopt. This makes them attractive model systems for investigations concerning the origin of eusociality. The rapidly accumulating information on primitively eusocial wasps suggests that haplodiploidy is unlikely to have an important role in the origin of eusociality. General kin selection (without help from haplodiploidy) could however have been an important factor due to the many advantages of group living. Pre-imaginal caste bias leading to variations in fertility is also likely to have some role. Because workers often have some chance of becoming reproductives in future, mutualism and other individual selection models suggest themselves as important factors. A hypothesis for the route to eusociality which focuses on the factors selecting for group living at different stages in social evolution is presented. It is argued that group living originates owing to the benefit of mutualism (the 'Gambling Stage') but parental manipulation and subfertility soon become important (the 'Manipulation Stage') and finally the highly eusocial state is maintained because genetic asymmetries created by haplodiploidy are exploited by kin recognition (the 'Recognition Stage').

Males, but not females, mate with multiple partners: a laboratory study of a primitively eusocial wasp Ropalidia marginata

Insect Soc., 2012

The intense interest in social Hymenoptera, on account of their elaborate sociality and the paradox of altruism, has often suffered from considerable gender imbalance. This is partly due to the fact that worker behaviour and altruism are restricted to the females and partly because males often live off the nest. Yet, understanding the males, especially in the context of mating biology is essential even for understanding the evolution of sociality. Mating patterns have a direct bearing on the levels of intra-colony genetic relatedness, which in turn, along with the associated costs and benefits of worker behaviour, are central to our understanding of the evolution of sociality. Although mating takes place away from the nest in natural colonies of the primitively eusocial wasp Ropalidia marginata, mating can be observed in the laboratory if a male and a female are placed in a transparent, aerated plastic container, and both wasps are in the range of 5-20 days of age. Here, we use this setup and show that males, but not females, mate serially with multiple partners. The multiple mating behaviour of the males is not surprising because in nature males have to mate with a number of females, only a few of whom will go on to lay eggs. The reluctance of R. marginata females to mate with multiple partners is consistent with the expectation of monogamy in primitively eusocial species with totipotent females, although the apparent discrepancy with a previous work with allozyme markers in natural colonies suggesting that females may sometimes mate with two or three different males remains to be resolved.