Polyethism is the term used for functional specialization of non-reproductive individuals in a colony of social organisms, particularly insects. Division of labour is considered a key aspect of eusociality and can be seen in a variety of forms. In some insects, there are distinct morphological differences among the individuals that decide their function in the colony, and this is termed as caste or morphological polyethism and is associated with polymorphism. Functions of individuals within the colony that are identical in morphology may however vary in the tasks taken up with the age of the individuals. In some species riskier activities are taken up by older individuals. This is termed as age polyethism. Time- and season-related specialization may also be termed more generically as temporal polyethism. The mechanisms involved in the control of polyethism has been an area of intense research in the field of sociobiology.
Experiments have been used to examine how polyethism is controlled under different circumstances in the colony. In honey bees younger workers work within the hive and it is only the older workers which are involved in outdoor tasks such as foraging. The application of juvenile hormone to worker honey bees has been shown to alter the tasks that they undertake indicating the involvement of hormonal control. [1] The flow of information from the nest environment related to the tasks that need to be undertaken, shortages, recruitment and the control of production of polymorphs by the reproductives has been an area of ongoing research. [2] [3] [4]
A honey bee is a eusocial flying insect within the genus Apis of the bee clade, all native to mainland Afro-Eurasia. After bees spread naturally throughout Africa and Eurasia, humans became responsible for the current cosmopolitan distribution of honey bees, introducing multiple subspecies into South America, North America, and Australia.
Waggle dance is a term used in beekeeping and ethology for a particular figure-eight dance of the honey bee. By performing this dance, successful foragers can share information about the direction and distance to patches of flowers yielding nectar and pollen, to water sources, or to new nest-site locations with other members of the colony.
Bombus terrestris, the buff-tailed bumblebee or large earth bumblebee, is one of the most numerous bumblebee species in Europe. It is one of the main species used in greenhouse pollination, and so can be found in many countries and areas where it is not native, such as Tasmania. Moreover, it is a eusocial insect with an overlap of generations, a division of labor, and cooperative brood care. The queen is monandrous which means she mates with only one male. B. terrestris workers learn flower colors and forage efficiently.
The dwarf honey bee, Apis florea, is one of two species of small, wild honey bees of southern and southeastern Asia. It has a much wider distribution than its sister species, Apis andreniformis. First identified in the late 18th century, Apis florea is unique for its morphology, foraging behavior and defensive mechanisms like making a piping noise. Apis florea have open nests and small colonies, which makes them more susceptible to predation than cavity nesters with large numbers of defensive workers. These honey bees are important pollinators and therefore commodified in countries like Cambodia.
Lasioglossum malachurum, the sharp-collared furrow bee, is a small European halictid bee. This species is obligately eusocial, with queens and workers, though the differences between the castes are not nearly as extreme as in honey bees. Early taxonomists mistakenly assigned the worker females to a different species from the queens. They are small, shiny, mostly black bees with off-white hair bands at the bases of the abdominal segments. L. malachurum is one of the more extensively studied species in the genus Lasioglossum, also known as sweat bees. Researchers have discovered that the eusocial behavior in colonies of L. malachurum varies significantly dependent upon the region of Europe in which each colony is located.
Apis andreniformis, or the black dwarf honey bee, is a relatively rare species of honey bee whose native habitat is the tropical and subtropical regions of Southeast Asia.
The East African lowland honey bee is a subspecies of the western honey bee. It is native to central, southern and eastern Africa, though at the southern extreme it is replaced by the Cape honey bee. This subspecies has been determined to constitute one part of the ancestry of the Africanized bees spreading through North and South America.
Spatial organization can be observed when components of an abiotic or biological group are arranged non-randomly in space. Abiotic patterns, such as the ripple formations in sand dunes or the oscillating wave patterns of the Belousov–Zhabotinsky reaction emerge after thousands of particles interact millions of times. On the other hand, individuals in biological groups may be arranged non-randomly due to selfish behavior, dominance interactions, or cooperative behavior. W. D. Hamilton (1971) proposed that in a non-related "herd" of animals, spatial organization is likely a result of the selfish interests of individuals trying to acquire food or avoid predation. On the other hand, spatial arrangements have also been observed among highly related members of eusocial groups, suggesting that the arrangement of individuals may provide some advantage for the group.
Task allocation and partitioning is the way that tasks are chosen, assigned, subdivided, and coordinated within a colony of social insects. Task allocation and partitioning gives rise to the division of labor often observed in social insect colonies, whereby individuals specialize on different tasks within the colony. Communication is closely related to the ability to allocate tasks among individuals within a group. This entry focuses exclusively on social insects. For information on human task allocation and partitioning, see division of labour, task analysis, and workflow.
The western honey bee or European honey bee is the most common of the 7–12 species of honey bees worldwide. The genus name Apis is Latin for "bee", and mellifera is the Latin for "honey-bearing" or "honey carrying", referring to the species' production of honey.
Eusociality, the highest level of organization of sociality, is defined by the following characteristics: cooperative brood care, overlapping generations within a colony of adults, and a division of labor into reproductive and non-reproductive groups. The division of labor creates specialized behavioral groups within an animal society which are sometimes referred to as 'castes'. Eusociality is distinguished from all other social systems because individuals of at least one caste usually lose the ability to perform at least one behavior characteristic of individuals in another caste. Eusocial colonies can be viewed as superorganisms.
Trigona spinipes is a species of stingless bee. It occurs in Brazil, where it is called arapuá, aripuá, irapuá, japurá or abelha-cachorro ("dog-bee"). The species name means "spiny feet" in Latin. Trigona spinipes builds its nest on trees, out of mud, resin, wax, and assorted debris, including dung. Therefore, its honey is not fit for consumption, even though it is reputed to be of good quality by itself, and is used in folk medicine. Colonies may have from 5,000 to over 100,000 workers.
A gamergate is a mated worker ant that can reproduce sexually, i.e., lay fertilized eggs that will develop as females. In the vast majority of ant species, workers are sterile and gamergates are restricted to taxa where the workers have a functional sperm reservoir ('spermatheca'). In some species, gamergates reproduce in addition to winged queens, while in other species the queen caste has been completely replaced by gamergates. In gamergate species, all workers in a colony have similar reproductive potentials, but as a result of physical interactions, a dominance hierarchy is formed and only one or a few top-ranking workers can mate and produce eggs. Subsequently however, aggression is no longer needed as gamergates secrete chemical signals that inform the other workers of their reproductive status in the colony.
Worker policing is a behavior seen in colonies of social hymenopterans whereby worker females eat or remove eggs that have been laid by other workers rather than those laid by a queen. Worker policing ensures that the offspring of the queen will predominate in the group. In certain species of bees, ants and wasps, workers or the queen may also act aggressively towards fertile workers. Worker policing has been suggested as a form of coercion to promote the evolution of altruistic behavior in eusocial insect societies.
Reticulitermes is a termite genus in the family Rhinotermitidae. They are found in most temperate regions on Earth including much of Asia and the Middle East, Western Europe, and all of North America.
An ergatoid is a permanently wingless reproductive adult ant or termite. The similar but somewhat ambiguous term ergatogyne refers to any intermediate form between workers and standard gynes. Ergatoid queens are distinct from other ergatogyne individuals in that they are morphologically consistent within a species and are always capable of mating, whereas inter caste individuals, another class of ergatogynes, often are not. Ergatoids can exhibit wide morphological differences between species, sometimes appearing almost identical to normal workers and other times being quite distinct from both workers and standard queens. In addition to morphological features, ergatoids among different species can exhibit a wide range of behaviors, with some ergatoids acting only as reproductives and others actively foraging. Ergatoid queens have developed among a large number of ant species, and their presence within colonies can often provide clues on the social structures of colonies and as to how new colonies are founded. Without wings, almost all species of ants that solely produce ergatoid queens establish new colonies by fission.
Megalopta genalis is a species of the family Halictidae, otherwise known as the sweat bees. The bee is native to Central and South America. Its eyes have anatomical adaptations that make them 27 times more sensitive to light than diurnal bees, giving it the ability to be nocturnal. However, its eyes are not completely different from other diurnal bees, but are still apposition compound eyes. The difference therefore lies purely in adaptations to become nocturnal, increasing the success of foraging and minimizing the danger of doing so from predation. This species has served as a model organism in studies of social behavior and night vision in bees.
This is a glossary of terms used in the descriptions of ants.
Social immunity is any antiparasite defence mounted for the benefit of individuals other than the actor. For parasites, the frequent contact, high population density and low genetic variability makes social groups of organisms a promising target for infection: this has driven the evolution of collective and cooperative anti-parasite mechanisms that both prevent the establishment of and reduce the damage of diseases among group members. Social immune mechanisms range from the prophylactic, such as burying beetles smearing their carcasses with antimicrobials or termites fumigating their nests with naphthalene, to the active defenses seen in the imprisoning of parasitic beetles by honeybees or by the miniature 'hitchhiking' leafcutter ants which travel on larger worker's leaves to fight off parasitoid flies. Whilst many specific social immune mechanisms had been studied in relative isolation, it was not until Sylvia Cremer et al.'s 2007 paper "Social Immunity" that the topic was seriously considered. Empirical and theoretical work in social immunity continues to reveal not only new mechanisms of protection but also implications for understanding of the evolution of group living and polyandry.
Insect cognition describes the mental capacities and study of those capacities in insects. The field developed from comparative psychology where early studies focused more on animal behavior. Researchers have examined insect cognition in bees, fruit flies, and wasps.