scholarly journals The effect of age on non-reproductive division of labour in the tropical primitively eusocial wasp, Ropalidia cyathiformis

2020 ◽  
Vol 64 (4-5-6) ◽  
pp. 267-273
Author(s):  
Sruthi Unnikrishnan ◽  
Raghavendra Gadagkar
Keyword(s):  
Division Of Labour ◽  
Age Polyethism ◽  
Relative Age ◽  
Eusocial Insects ◽  
Primitively Eusocial Wasp ◽  
Eusocial Wasp ◽  
Reproductive Division Of Labour ◽  
Absolute Age ◽  
Reproductive Division ◽  
Primitively Eusocial

Division of labour among workers (non-reproductive division of labour), a characteristic feature of eusocial insects enables the efficient functioning of their colonies. In many advanced insect societies division of labour is based on age (age polyethism). Primitively eusocial insects however are believed to have a weak age polyethism. Here we investigated the role of age in non-reproductive division of labour in the tropical primitively eusocial wasp, Ropalidia cyathiformis and compared it with that in Ropalidia marginata, a congeneric species that exhibits relatively strong age polyethism. Age had a significant effect on the first performance of the four tasks studied; tasks were initiated in the sequence feed larva, build, bring food and bring building material. We measured task performance as the absolute frequency of tasks performed (FTP) and the probability of performing a task relative to other tasks (PTP) and age as absolute age in days since eclosion as well as relative age compared to nestmates. FTP varied significantly with both absolute and relative age, although absolute age explained more variance. PTP varied significantly with absolute age but not always with relative age. This is contrary to R. marginata, where more variation is explained by relative age than by absolute age. There was no trade-off between intranidal and extranidal tasks in R. cyathiformis unlike in R. marginata where the frequency of intranidal tasks decreased and that of extranidal tasks increased with age. We conclude that age polyethism is weak and less flexible in R. cyathiformis compared to that in R. marginata.

Ergonomic skew and reproductive queuing based on social and seasonal variation in foraging activity of eastern carpenter bees (Xylocopa virginica)

2015 ◽  
Vol 93 (8) ◽  
pp. 615-625 ◽  
Author(s):  
M.H. Richards ◽  
C. Course
Keyword(s):  
Division Of Labour ◽  
Foraging Activity ◽  
Dominance Hierarchies ◽  
Carpenter Bee ◽  
Eusocial Insects ◽  
Carpenter Bees ◽  
Behavioural Interactions ◽  
Reproductive Division Of Labour ◽  
Xylocopa Virginica ◽  
Reproductive Division

Reproductive division of labour in social carpenter bees differs from that in classically eusocial insects because reproductive output and ergonomic inputs are positively correlated—dominant females monopolize both foraging and reproduction. We quantified ergonomic skew in the facultatively social bee Xylocopa virginica (L., 1771) (eastern carpenter bee) based on detailed observations of foraging activity by individually marked females in 2009. Unusually for a univoltine bee, this species exhibits a spring foraging phase during which females feed pollen to other adults, probably as part of behavioural interactions to establish dominance hierarchies. During brood-provisioning, foraging in social nests was dominated by one female at a time, with replacement by a succession of foragers as dominants disappeared and were succeeded by a subordinate. The principal foragers (individuals that did the largest share of foraging in each colony) did 85%–100% of all pollen trips, so contributions to pollen-provisioning by female nest mates were highly uneven. Individual foraging rate was unaffected by group size and total colony foraging effort was a function of the number of foragers per group. Transient females that moved to new nests were as successful in achieving dominant forager status as females resident in their natal nests. This evidence indicates that colony social organisation is based on reproductive queues, whereby the first-ranked bee is the dominant forager and subordinates queue for opportunities to replace her.

scholarly journals Nutrition induced direct fitness for workers in a primitively eusocial wasp

2021 ◽  
Author(s):  
J. U. Krishnan ◽  
A. Brahma ◽  
S. K. Chavan ◽  
R. Gadagkar
Keyword(s):  
Caste Differentiation ◽  
Egg Laying ◽  
Ropalidia Marginata ◽  
Eusocial Insects ◽  
Primitively Eusocial Wasp ◽  
Direct Fitness ◽  
Queen Replacement ◽  
Eusocial Wasp ◽  
Ad Libitum ◽  
Primitively Eusocial

AbstractEusocial insects are characterised by a reproductive caste differentiation such that egg-laying is restricted to a small number of queens. The majority of the colony members function as non-reproducing workers and gain indirect fitness by rearing the offspring of the reproductives. In primitively eusocial species, some workers can also get direct fitness by sneaking in some eggs in the presence of the queens, replacing the queens and becoming new queens, or initiating new nests. Here we aimed to understand the factors that permit some workers to gain direct fitness and alter the number of workers doing so, using the primitively eusocial wasp Ropalidia marginata. We transplanted 12 naturally occurring colonies into large laboratory cages where there was adequate space for the workers to leave their natal nests and initiate new colonies. We compared six control colonies that we provided with ad libitum food placed near the nest to six test colonies in which we hand-fed the wasps in addition to the ad libitum food. Wasps in test colonies consumed more food, showed more aggression, replaced their queens, and initiated new nests significantly more often than those in control colonies. When considering all 12 colonies, the rates of queen replacement and nest foundation were significantly positively correlated with food consumption rates. The additional nutrition gained by hand-fed wasps appears to help workers in test colonies to develop their ovaries and lay eggs, implying that they are nutritionally castrated in control colonies.

scholarly journals Suppressed eusocial reproduction supports evolutionary convergence over co-option

2021 ◽  
Author(s):  
Mariana Velasque ◽  
Tan Yongkai ◽  
Andrew W Liu ◽  
Nicholas M Luscombe ◽  
Jai A Denton
Keyword(s):  
Physiological Response ◽  
Convergent Evolution ◽  
Division Of Labour ◽  
Reproductive Capacity ◽  
Eusocial Insects ◽  
Reproductive Life ◽  
Reproductive Division Of Labour ◽  
Eusocial Animals ◽  
Or Genes ◽  
Reproductive Division

Eusocial insects are characterized by the presence of division of labour between reproductive (i.e. workers) and non-reproductive (i.e. queens) individuals. In eusocial insects, such as wasps, ants, honeybees and termites, such reproductive division of labour is mediated by the use of unique pheromones. In eusocial animals, pheromones control two distinct aspects of the division of labour: reproduction and division of tasks amongst workers. It has been suggested that eusociality arose independently on several occasions from pheromone-mediated co-option of pathways regulating the reproductive life cycle of solitary insects. Transcriptomic analysis has supported the co-option of similar pathways in each independently evolved eusocial insect. Using a solitary insect model, we sought to determine if these similar transcriptomic signals resulted from the co-option of similar pathways or varying pathways subject to convergent evolution. We measured the transcriptomic and physiological response of Drosophila melanogaster to pheromones from bumblebees, honey bees, and termites. In each case we observed a strong physiological response - the reduction of ovary size. However, employing conventional differential gene expression analysis and several forms of network analysis, we were unable to detect any conserved pathway or genes acting as a primer for eusociality. This strongly suggests that pheromone-mediated eusociality is the result of convergent evolution. Wherein a physiological response, such as reduced reproductive capacity, acts as the primer for eusociality and is subsequently refined.

scholarly journals Colony size predicts division of labour in attine ants

2014 ◽  
Vol 281 (1793) ◽  
pp. 20141411 ◽  
Author(s):  
Henry Ferguson-Gow ◽  
Seirian Sumner ◽  
Andrew F. G. Bourke ◽  
Kate E. Jones
Keyword(s):  
Colony Size ◽  
Social Complexity ◽  
Inclusive Fitness ◽  
Size Variation ◽  
Division Of Labour ◽  
Eusocial Insects ◽  
Attine Ants ◽  
Reproductive Division Of Labour ◽  
Complexity Hypothesis ◽  
Reproductive Division

Division of labour is central to the ecological success of eusocial insects, yet the evolutionary factors driving increases in complexity in division of labour are little known. The size–complexity hypothesis proposes that, as larger colonies evolve, both non-reproductive and reproductive division of labour become more complex as workers and queens act to maximize inclusive fitness. Using a statistically robust phylogenetic comparative analysis of social and environmental traits of species within the ant tribe Attini, we show that colony size is positively related to both non-reproductive (worker size variation) and reproductive (queen–worker dimorphism) division of labour. The results also suggested that colony size acts on non-reproductive and reproductive division of labour in different ways. Environmental factors, including measures of variation in temperature and precipitation, had no significant effects on any division of labour measure or colony size. Overall, these results support the size–complexity hypothesis for the evolution of social complexity and division of labour in eusocial insects. Determining the evolutionary drivers of colony size may help contribute to our understanding of the evolution of social complexity.

scholarly journals Cooperation between non-relatives in a primitively eusocial paper wasp, Polistes dominula

2016 ◽  
Vol 371 (1687) ◽  
pp. 20150093 ◽  
Author(s):  
Jeremy Field ◽  
Ellouise Leadbeater
Keyword(s):  
Paper Wasp ◽  
Eusocial Insects ◽  
Polistes Dominula ◽  
Primitively Eusocial Wasp ◽  
The Social ◽  
Eusocial Wasp ◽  
Close Relatives ◽  
Recognition Errors ◽  
Primitively Eusocial

In cooperatively breeding vertebrates, the existence of individuals that help to raise the offspring of non-relatives is well established, but unrelated helpers are less well known in the social insects. Eusocial insect groups overwhelmingly consist of close relatives, so populations where unrelated helpers are common are intriguing. Here, we focus on Polistes dominula— the best-studied primitively eusocial wasp, and a species in which nesting with non-relatives is not only present but frequent. We address two major questions: why individuals should choose to nest with non-relatives, and why such individuals participate in the costly rearing of unrelated offspring. Polistes dominula foundresses produce more offspring of their own as subordinates than when they nest independently, providing a potential explanation for co-founding by non-relatives. There is some evidence that unrelated subordinates tailor their behaviour towards direct fitness, while the role of recognition errors in generating unrelated co-foundresses is less clear. Remarkably, the remote but potentially highly rewarding chance of inheriting the dominant position appears to strongly influence behaviour, suggesting that primitively eusocial insects may have much more in common with their social vertebrate counterparts than has commonly been thought.

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