Ecology and Social Organisation of Wasps

Abstract

Understanding sociality is a general question in biology: it tells us how groups evolve and function, from cells to insect societies. The social wasps (Hymenoptera and Vespidae) display a wide range of diversity in their ecology and social organisation, providing insights into the origins of simple societies and the elaboration and maintenance of complex societies. Social wasps play an important role in our ecosystems and economies, for example, through their pollination and pest control services. Compared with other social insects (e.g. ants, termites and bees), the social wasps are understudied. Here the authors give a brief overview of the social wasps, their phylogenetic history, diversity in social organisation and explain how they offer important insights on the key innovations underpinning the evolution of sociality. Key Concepts: Wasps make up a huge group of social insects, yet only one‐fifth of them exhibit social behaviour. Social wasps are ideal and unique models for studying social evolution as they show the full spectrum of social organisation and behaviours. Across the social spectrum, wasp species show a number of key innovations that have contributed to their success, including the transition to group living, the evolution of castes, policing and swarm founding. The evolution of caste differentiation has led to mutual dependency between phenotypes within species, and this is likely to have facilitated increased social complexity. Studying both proximate and ultimate factors of social evolution will allow us to better understand the mechanisms of social evolution in wasps and reduce confusion in the theory of sociobiology.

Ecosystem services provided by aculeate wasps

“…Although the social wasps account for less than 3% of all wasp species (Aguiar et al ., 2013; Bell & Sumner, 2013), their ecological impact as predators is likely to be highly significant because of their large colony sizes, with hundreds to thousands of workers and brood accounting for a large amount of biomass in ecosystems (Thomas et al ., 1990; Wilson, 1990; Elizalde et al ., 2020). Adult wasps forage for water, wood pulp, nectar and, most importantly, protein (Spradbery, 1973; Richter, 2000).…”

A molecular concept of caste in insect societies

“…Determining precisely the traits used to classify individuals into castes has important implications for the study of eusocial evolution. Indeed, the degree to which castes are differentiated is a key characteristic used to infer the level of social complexity a species occupies, and by inference, what stage in the process of social evolution it may represent [6,16]. The importance of this is illustrated by the recent debate over whether all eusocial species are in fact 'superorganisms' and truly represent a major transition in evolution [7].…”

“…The evolution of queen and worker castes is the key to the ecological success of these insects [1,2]. It is not surprising, therefore, that in the quest to understand how and why eusociality evolves, researchers have focused on revealing the mechanisms, evolution and function of castes [3][4][5][6]. A long-debated issue is the equivalent use of the term 'queen' and 'worker' to describe division of labour across all types of eusocial societies, and specifically: is the concept of caste theoretically relevant [4,7] and empirically meaningful for the simple eusocial societies?…”

Social wasps as models to study the major evolutionary transition to superorganismality

“…Polistes paper wasps) to species with the most complex societies in which the colony can be considered an individual (super)organism in its own right (where division of labour is fixed during development, irreversibly; e.g. Vespula yellow-jacket wasps) [4].…”