Eusocial in the context of Vespula

A caste is a fixed social group into which an individual is born within a particular system of social stratification: a caste system. Within such a system, individuals are expected to marry exclusively within the same caste (endogamy), follow lifestyles often linked to a particular occupation, hold a ritual status observed within a hierarchy, and interact with others based on cultural notions of exclusion, with certain castes considered as either more pure or more polluted than others. The term "caste" is also applied to morphological groupings in eusocial insects such as ants, bees, and termites.

The paradigmatic ethnographic example of caste is the division of India's Hindu society into rigid social groups. Its roots lie in South Asia's ancient history and it still exists; however, the economic significance of the caste system in India seems to be declining as a result of urbanisation and affirmative action programs. A subject of much scholarship by sociologists and anthropologists, the Hindu caste system is sometimes used as an analogical basis for the study of caste-like social divisions existing outside Hinduism and India. In colonial Spanish America, mixed-race castas were a category within the Hispanic sector but the social order was otherwise fluid.

A honey bee (also spelled honeybee) is a eusocial flying insect from the genus Apis of the largest bee family, Apidae. Honey bees are known for their construction of perennial nests within cavities (i.e. beehives) containing hexagonal cells made of secreted wax, their large colony sizes, and their routine regurgitation of digested carbohydrates as surplus food storage in the form of honey, the lattermost of which distinguishes their hives as a prized foraging target of many mellivorous animals including honey badgers, bears and human hunter-gatherers.

Although honey bees represent only a small fraction of the roughly 20,000 known species of bees, they are the bee clade most familiar to humans and are also the most valuable beneficial insects to agriculture and horticulture. The best-known honey bee species is the western honey bee (Apis mellifera), which was domesticated and farmed (i.e. beekeeping) for honey production and crop pollination. The only other domesticated species is the eastern honey bee (Apis cerana), which are raised in South, Southeast and East Asia.

The Vespidae are a large (nearly 5000 species), diverse, cosmopolitan family of wasps, including nearly all the known eusocial wasps (such as Polistes fuscatus, Vespa orientalis, and Vespula germanica) and many solitary wasps. Each social wasp colony includes a queen and a number of female workers with varying degrees of sterility relative to the queen. In temperate social species, colonies usually last only one year, dying at the onset of winter. New queens and males (drones) are produced towards the end of the summer, and after mating, the queens hibernate over winter in cracks or other sheltered locations. The nests of most species are constructed out of mud, but polistines and vespines use plant fibers, chewed to form a sort of paper (also true of some stenogastrines). Many species are pollen vectors contributing to the pollination of several plants, being potential or even effective pollinators, while others are notable predators of pest insect species, and a few species are invasive pests.

The subfamilies Polistinae and Vespinae are composed solely of eusocial species, while the Eumeninae, Euparagiinae, Gayellinae, Masarinae and Zethinae are all solitary with the exception of a few communal and several subsocial species. The Stenogastrinae are facultatively eusocial, considering nests may have one or several adult females; in cases where the nest is shared by multiple females (typically, a mother and her daughters) there is reproductive division of labor and cooperative brood care.

An ant colony is a population of ants, typically from a single species, capable of maintaining their complete lifecycle. Ant colonies are eusocial, communal, and efficiently organized and are very much like those found in other social Hymenoptera, though the various groups of these developed sociality independently through convergent evolution. The typical colony consists of one or more egg-laying queens, numerous sterile females (workers, soldiers) and, seasonally, many winged sexual males and females. In order to establish new colonies, ants undertake flights that occur at species-characteristic times of the day. Swarms of the winged sexuals (known as alates) depart the nest in search of other nests. The males die shortly thereafter, along with most of the females. A small percentage of the females survive to initiate new nests.

Aculeata is an infraorder of Hymenoptera containing ants, bees, and stinging wasps. The name is a reference to the defining feature of the group, which is the modification of the ovipositor into a stinger. However, many members of the group cannot sting, either retaining the ovipositor, or having lost it altogether. A large part of the clade is parasitic.

This group includes all of the eusocial Hymenopterans.

The Polistinae is a subfamily of eusocial wasps belonging to the family Vespidae. They are closely related to the wasps (“yellowjackets” as they are called in North America) and true hornets of the subfamily Vespinae, containing four tribes. With about 1,100 species total, it is the second-most diverse subfamily within the Vespidae, and while most species are tropical or subtropical, they include some of the most frequently encountered large wasps in temperate regions.

The English common name for Polistinae is paper wasp. Many polistines, such as Polistes fuscatus, Polistes annularis, and Polistes exclamans, make their nests out of paper. Despite being called paper wasps, other wasps (including the wasps in the subfamily Vespinae) also build nests out of paper. Additionally, some epiponine wasps (such as Polybia emaciata) build their nests out of mud despite being Polistinae.

Blattodea is an order of insects that contains cockroaches and termites. Collectively, Blattodea and the mantis order Mantodea are considered part of the superorder Dictyoptera. Formerly, termites were considered the separate order Isoptera, but genetic and molecular evidence suggests they evolved from within the cockroach lineage, which renders them cockroaches cladistically; the group of termites were subsumed into Blattodea and they are considered by some to be a divergent group of cockroaches. Blattodea includes approximately 4,400 species of cockroach in almost 500 genera, and about 3,000 species in around 300 genera within the termite clade.

Termites are pale-coloured, soft-bodied eusocial insects that live in colonies with a biological caste system. A pair of sexually mature reproductives, the king and the queen, breed to produce all other individuals within the colony, consisting of the numerous and sterile (non-breeding) workers and soldiers. In contrast, cockroaches are pigmented (often brown) and possess sclerotised body parts hardened with sclerotin. Cockroaches are not colonial but do have a tendency to aggregate, with some species considered to be pre-social as all adults within a social group are capable of breeding. Termites and cockroaches share several similarities, including various social behaviours, trail following, kin recognition, and methods of communication.

Myrmecology (/mɜːrmɪˈkɒlədʒi/; from Greek: μύρμηξ, myrmex, "ant" and λόγος, logos, "study") is a branch of entomology focusing on the study of ants. Ants continue to be a model of choice for the study of questions on the evolution of social systems because of their complex and varied forms of social organization. Their diversity and prominence in ecosystems also has made them important components in the study of biodiversity and conservation. In the 2000s, ant colonies began to be studied and modeled for their relevance in machine learning, complex interactive networks, stochasticity of encounter and interaction networks, parallel computing, and other computing fields.

Dolichovespula is a small genus of social wasps distributed widely throughout the Northern Hemisphere. The yellow and black members of the genus are known by the common name yellowjackets in North America, such as Dolichovespula norwegica, along with members of their sister genus Vespula. In a study on the nesting biology of Dolichovespula, a colony of D. maculata with 771 workers was reported as having the largest recorded population count.

The European hornet (Vespa crabro) is the largest eusocial wasp native to Europe. It is also the only true hornet (genus Vespa) found in North America, having been introduced to the United States and Canada from Europe as early as 1840. Vespines, such as V. crabro, are known for making intricate paper-like nests out of surrounding plant materials and other fibers. Unlike most other vespines, reproductive suppression involves worker policing instead of queen pheromone control, as was previously thought.

This species stings in response to being stepped on or grabbed, but generally avoids conflict. It is also defensive of its nest and can be aggressive around food sources. Care should be taken when they are found in these circumstances, as they may sting without warning. European hornets are largely carnivorous and hunt large insects such as beetles, wasps, large moths, dragonflies, and mantises. They also feed on fallen fruit and other sources of sugary food. Mutual predation between medium-sized hornets and the Asilidae (robber flies) is often reported.