Seasonally Variable Eusocially Selected Traits in the Paper Wasp, Mischocyttarus mexicanus (original) (raw)
Related papers
Division of Labor in Colonies of the Eusocial Wasp, Mischocyttarus consimilis
Journal of Insect Science, 2012
The division of labor between castes and the division of labor in workers according to age (temporal polyethism) in social wasps are crucial for maintaining social organization. This study evaluated the division of labor between castes, and the temporal polyethism in workers of Mischocyttarus consimilis Zikán (Hymenoptera: Vespidae). To describe the behavioral repertory of this species, observations were made of 21 colonies, with 100 hours of observations. In order to observe temporal polyethism, each newly emerged wasp was marked with colored dots on the upper area of the thorax. This allowed the observation of behavioral acts performed by each worker from the time of emergence to its death. Through hybrid multidimensional scaling, a clear division between queens and workers could be identified, in which the behaviors of physical dominance and food solicitation characterized the queen caste; while behaviors such as adultadult trophallaxis, destruction of cells, alarm, foraging for prey, foraging for nectar, and unsuccessful foraging characterized the worker caste. Hybrid multidimensional scaling characterized two groups, with intra-nest activities preferentially accomplished by younger workers, while extra-nest activities such as foraging were executed more frequently by older workers.
Entomon, 1991
When freshly eclosed females of the primitively eusocial wasp, Ropalidia marginata are isolated into individual cages, only about half of tliem build nests and lay eggs and those that do so take a long and variable amount of thne (Mean ± S D = 66 ± 37 days) before they lay their first egg. Part of the reason for this delay is because, when kept in isolation, no wasp begins to lay eggs during a period of approximately 82 days from mid-October to early January. Wasps maintained at a constant temperature of 26±1°C however initiate egg laying throughout the year, suggesting that the low temperatures during mid-October to early January may be at least one factor that makes this period unfavourable for wasps maintained at room temperature. Egg laying continues more or less normally throughout October-January however, in all natural and laboratory colonies studied. Natural colonies of R. marginata are initiated throughout the year and often by groups of females. Huddling together is a striking feature of the wasps especially on cold mornings. We therefore suggest that the isolated animals in our experiment are unable to lay eggs during the coldest part of the year because of their inability to huddle together, share metabolic heat and perform "co-operative thermoregulation". Such "co-operative thermoregulation" may thus be another factor that facilitates the evolution of sociality.
Chemoecology, 2020
Chemical communication is pivotal for social insects to ensure proper functioning of their colonies. Cuticular hydrocarbons (CHCs) are the most well-known class of compounds used to regulate different types of behavioural interaction within a social context. Queens of highly eusocial insects rely on the use of chemical communication to keep their reproductive monopoly, whereas queens of primitively eusocial insects often exert physical control to maintain reproductive dominance. However, in the past years, ample evidence has demonstrated that primitively eusocial insects also use chemical compounds to communicate. Based on this evidence, we aimed to elucidate whether CHCs carry some information regarding female hierarchical position, ovary activation and nestmate recognition in the primitively eusocial wasp Mischocyttarus parallelogrammus. Additionally, females were classified by their ovary activation. Finally, the cuticular profiles of females originating from different nests were compared to check whether CHCs convey information about their nest of origin. Our results confirmed that the chemical composition of alpha and subordinate females differed significantly in post-worker emergence nests, but that alpha and beta females surprisingly were not chemically different from each other in either of the colony phases. Furthermore, females with activated ovaries expressed a chemical profile distinct from that of females with non-activated ovaries. Lastly, we showed that CHCs might convey information about nest origin, since females hailing from different nests showed distinct chemical profiles. Based on our results, we conclude that CHCs might play a critical role in the nest-functioning of M. parallelogrammus, since they mirror social status.
Ecology Letters, 2015
Ecological constraints on independent breeding are recognised as major drivers of cooperative breeding across diverse lineages. How the prevalence and degree of cooperative breeding relates to ecological variation remains unresolved. Using a large data set of cooperative nesting in Polistes wasps we demonstrate that different aspects of cooperative breeding are likely to be driven by different aspects of climate. Whether or not a species forms cooperative groups is associated with greater short-term temperature fluctuations. In contrast, the number of cooperative foundresses increases in more benign environments with warmer, wetter conditions. The same data set reveals that intraspecific responses to climate variation do not mirror genus-wide trends and instead are highly heterogeneous among species. Collectively these data suggest that the ecological drivers that lead to the origin or loss of cooperation are different from those that influence the extent of its expression within populations.
To leave or to stay: direct fitness through natural nest foundation in a primitively eusocial wasp
Insectes Sociaux, 2019
Dispersing from the natal nest to found new nests is an avenue for gaining direct fitness for workers in some primitively eusocial insects, especially in species with a perennial nesting cycle where males are present throughout the year. Such nest foundation is difficult to study in nature or in small laboratory cages. Hence, we have investigated the dynamics of nest foundation by workers of the primitively eusocial wasp Ropalidia marginata inside closed walk-in cages so that we could locate and observe every event of nest foundation. Starting with nine parent nests we observed the dispersal of female workers that initiated 9 single-foundress and 20 multiple-foundress nests. Wasps congregated outside their parent nests and engaged in dominance-subordinate interactions before initiating multiple foundress nests. The most dominant wasps of such aggregations became queens, and among the others, some joined the new nests as cofoundresses to become workers while the others remained in the parent nests. Solitary foundresses never participated in such off-nest aggregations. Solitary foundresses and future queens of multiple foundress nests engaged in self-feeding behaviour outside their parent nests, a behaviour not performed by wasps that did not initiate new nests. Queens of new nests gained immediate direct fitness. Although the cofoundresses continued to gain only indirect fitness, they are expected to have a higher probability of gaining direct fitness in the future as compared to the corresponding probability in their much larger parent nests. These findings underscore the importance of direct fitness in the evolution of cooperation in primitively eusocial insects.
Why Wasp Foundresses Change Nests: Relatedness, Dominance, and Nest Quality
2012
The costs and benefits of different social options are best understood when individuals can be followed as they make different choices, something that can be difficult in social insects. In this detailed study, we follow overwintered females of the social wasp Polistes carolina through different nesting strategies in a stratified habitat where nest site quality varies with proximity to a foraging area, and genetic relatedness among females is known. Females may initiate nests, join nests temporarily or permanently, or abandon nests.
Behavioural Processes, 2014
In many primitively eusocial wasp species new nests are founded either by a single female or by a small group of females. In the single foundress nests, the lone female develops her ovaries, lays eggs as well as tends her brood. In multiple foundress nests social interactions, especially dominance-subordinate interactions, result in only one 'dominant' female developing her ovaries and laying eggs. Ovaries of the remaining 'subordinate' cofoundresses remain suppressed and these individuals function as workers and tend the dominant's brood. Using the tropical, primitively eusocial polistine wasp Ropalidia marginata and by comparing wasps held in isolation and those kept as pairs in the laboratory, we demonstrate that social interactions affect ovarian development of dominant and subordinate wasps among the pairs in opposite directions, suppressing the ovaries of the subordinate member of the pair below that of solitary wasps and boosting the ovaries of dominant member of the pair above that of solitary females. In addition to being of physiological interest, such mirror image effects of aggression on the ovaries of the aggressors and their victims, suggest yet another mechanism by which subordinates can enhance their indirect fitness and facilitate the evolution of worker behavior by kin selection.