Physogastrism or physogastry is a characteristic of certain arthropods (mostly insects and mites), where the abdomen is greatly enlarged and membranous. The most common examples are the "queens" of certain species of eusocial insects such as termites, bees and ants, in which the abdomen swells in order to hold enlarged ovaries, thus increasing fecundity. This means that the queen has the ability to hold more and produce more eggs at one time. Physogastric queens produce an enormous number of eggs which can account for a significant amount of their body weight. In the termite species Macrotermes subhyalinus , eggs can make up a third of their body weight, and a 15-gram queen can produce up to 30 eggs per minute. The physogastric queens' egg production is supported by oocyte proteins supplied by the "queen body fat." [1]
Physogastrism in termites presents itself in quite an unusual manner. Unlike most physogastric insects, the queen termite is able to increase its size without the use of cuticular molting. Rather, the queen unfolds and stretches her abdominal epicuticle in order to make room for the subsequent egg deposits. This process has been observed to be incredibly slow (sometimes over the course of several years). [2]
Many stingless bee species have physogastric queens, such as the South American species Paratrigona subnuda and Schwarziana quadripunctata . [3] Physogastrism can also be seen in the stingless bee species Melipona bicolor , which is facultatively polygynous, and therefore one or more physogastric queens can be found in the same colony. [4] These queens interact with each other within the colony, and during the patrolling phase, a queen may attempt to touch the abdomen of another queen. The other queen turns her abdomen away, and what follows is the two queens circling one another, trying to touch the other's abdomen; as such, the queens are almost always active. [5]
Various lineages of non-social insects demonstrate various degrees of physogastry, especially among females. The most dramatic and best-known are among the beetles, especially certain groups that live inside ant or termite nests, where the distended abdomen is thought to enhance integration into their hosts' colonies, [6] [7] though it is also seen in several herbivorous beetle lineages such as Chrysomelidae (e.g., Gastrophysa ) and Meloidae (e.g., Megetra ).
Females of endoparasitic fleas, in particular in the genus Tunga , exhibit severe physogastry once they have penetrated the host's skin and begun to produce eggs.
Many Acari (ticks and mites) have physogastric females, sometimes involving precocious development of offspring inside the mother's body. [8]
Termites are small insects that live in colonies and have distinct castes (eusocial) and feed on wood or other dead plant matter, occurring on every continent except Antarctica. Termites comprise the infraorder Isoptera, or alternatively the epifamily Termitoidae, within the order Blattodea. Termites were once classified in a separate order from cockroaches, but recent phylogenetic studies indicate that they evolved from cockroaches, as they are deeply nested within the group, and the sister group to wood eating cockroaches of the genus Cryptocercus. Previous estimates suggested the divergence took place during the Jurassic or Triassic. More recent estimates suggest that they have an origin during the Late Jurassic, with the first fossil records in the Early Cretaceous. About 3,106 species are currently described, with a few hundred more left to be described. Although these insects are often called "white ants", they are not ants, and are not closely related to ants.
A honey bee is a eusocial flying insect within the genus Apis of the bee clade, all native to 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.
A worker bee is any female (eusocial) bee that lacks the full reproductive capacity of the colony's queen bee; under most circumstances, this is correlated to an increase in certain non-reproductive activities relative to a queen. While worker bees occur in all eusocial bee species, the term is rarely used for any bees other than honey bees.
Histeridae is a family of beetles commonly known as clown beetles or Hister beetles. This very diverse group of beetles contains 3,900 species found worldwide. They can be easily identified by their shortened elytra that leaves two of the seven tergites exposed, and their geniculate (elbowed) antennae with clubbed ends. These predatory feeders are most active at night and will fake death if they feel threatened. This family of beetles will occupy almost any kind of niche throughout the world. Hister beetles have proved useful during forensic investigations to help in time of death estimation. Also, certain species are used in the control of livestock pests that infest dung and to control houseflies. Because they are predacious and will even eat other Hister beetles, they must be isolated when collected.
The spermatheca, also called receptaculum seminis, is an organ of the female reproductive tract in insects, e.g. ants, bees, some molluscs, oligochaeta worms and certain other invertebrates and vertebrates. Its purpose is to receive and store sperm from the male or, in the case of hermaphrodites, the male component of the body. Spermathecae can sometimes be the site of fertilization when the oocytes are sufficiently developed.
Stingless bees, sometimes called stingless honey bees or simply meliponines, are a large group of bees, comprising the tribe Meliponini. They belong in the family Apidae, and are closely related to common honey bees, carpenter bees, orchid bees, and bumblebees. Meliponines have stingers, but they are highly reduced and cannot be used for defense, though these bees exhibit other defensive behaviors and mechanisms. Meliponines are not the only type of "stingless" bee; all male bees and many female bees of several other families, such as Andrenidae, also cannot sting. Some stingless bees have painful and powerful bites.
The gyne is the primary reproductive female caste of social insects. Gynes are those destined to become queens, whereas female workers are typically barren and cannot become queens. Having a queen is what makes a "queenright" hive, nest, or colony of eusocial insects. A colony with multiple queens is said to be a polygyne form, whereas one with only one is a monogyne form.
Schwarziana quadripunctata is a small, stingless bee found in a stretch of the South American Amazon from Goiás, Brazil, through Paraguay, to Misiones, Argentina. This highly eusocial insect constructs earthen nests in the subterranean level of the subtropical environment, an unusual feature among other stingless bees. The species ranges in sizes from 6.0 to 7.5 millimetres and feeds on a diverse diet of flowering plants found abundantly on the forest floor, including guacatonga and the mistletoe species Struthanthus concinnus.
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.
Tetragonula carbonaria is a stingless bee, endemic to the north-east coast of Australia. Its common name is sugarbag bee. They are also occasionally referred to as bush bees. The bee is known to pollinate orchid species, such as Dendrobium lichenastrum, D. toressae, and D. speciosum. It has been identified as an insect that collects pollen from the cycad Cycas media. They are also known for their small body size, reduced wing venation, and highly developed social structure comparable to honey bees.
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.
Bombus frigidus, the frigid bumblebee, is a rare species of bumblebee largely found in Canada and parts of the United States.
Melipona bicolorLepeletier, 1836, commonly known as Guaraipo or Guarupu, is a eusocial bee found primarily in South America. It is an inhabitant of the Araucaria Forest and the Atlantic Rainforest, and is most commonly found from South to East Brazil, Bolivia, Argentina, and Paraguay. It prefers to nest close to the soil, in hollowed trunks or roots of trees. M. bicolor is a member of the tribe Meliponini, and is therefore a stingless bee. This species is unique among the stingless bees species because it is polygynous, which is rare for eusocial bees.
Melipona beecheii is a species of eusocial stingless bee. It is native to Central America from the Yucatán Peninsula in the north to Costa Rica in the south. M. beecheii was cultivated in the Yucatán Peninsula starting in the pre-Columbian era by the ancient Maya civilization. The Mayan name for M. beecheii is xunan kab, which translates roughly to "regal lady bee". M. beecheii serves as the subject of various Mayan religious ceremonies.
Melipona subnitida is a neotropical bee species in the Apidae family found in the dry areas of Northeastern Brazil. This species of stingless bees practices single mating, monogynous habits.
Scaptotrigona postica is a species of stingless bee that lives mainly in Brazil. It is a eusocial bee in the tribe Meliponini. S. postica is one of 25 species in the genus Scaptotrigona and is a critical pollinator of the tropical rain forests of Brazil. They construct their nests in hollowed sections of tree trunks, allowing for effective guarding at the nest entrance. This species shows colony structure similar to most members of the Meliponini tribe with three roles within the colony: queen, worker, and male. S. postica individuals have different forms of communication from cuticular hydrocarbons to pheromones and scent trails. Communication is especially useful during worker foraging for nectar and pollen through the Brazilian tropical rain forests. S. postica is a very important pollinator of the Brazilian tropical rain forests and is widely appreciated for its honey. Stingless bees account for approximately 30% of all pollination of the Brazilian Caatinga and Pantanal ecosystems and up to 90% of the pollination for many species of the Brazilian Atlantic Forest and the Amazon.
Paratrigona subnuda, commonly known as the jataí-da-terra, is a species of eusocial stingless bee in the family Apidae and tribe Meliponini. These social bees are prevalent in Neotropical moist forests, including Brazilian Atlantic and other South American forests. They inhabit spherical nests in moist underground environments with their forest habitats. Within their Neotropical habitats the P. subnuda is considered to be a very successful and common species of bee. P. subnuda’s main source of food is pollen and nectar from a large variety of native Mesoamerican tropical plants. They have been extensively studied due to social conflicts arising from single mate behaviors and particular virgin behaviors. P. subnuda also exhibits the particular daily behavior in which they open the nest entrance at dawn and close the entrance at dusk when all their activities are done.
Melipona quadrifasciata is a species of eusocial, stingless bee of the order Hymenoptera. It is native to the southeastern coastal states of Brazil, where it is more commonly known as mandaçaia, which means "beautiful guard," as there is always a bee at the narrow entrance of the nest. M. quadrifasciata constructs mud hives in the hollows of trees to create thin passages that only allow one bee to pass at a time. Because they are stingless bees, M. quadrifasciata is often used as pollinators in greenhouses, outperforming honey bees in efficiency and leading to overall larger yields of fruits that were heavier, larger, and contained more seeds.
Melipona scutellaris is a eusocial stingless bee species of the order Hymenoptera and the genus Melipona. It is considered to be the reared Melipona species with the largest distribution in the North and Northeast regions of Brazil, with records from Rio Grande do Norte down to Bahia. Its common name, Uruçu, comes from the Tupi "eiru su", which in this indigenous language means "big bee". Their honey is highly desirable and the materials they create for nests have been proven to be a promising source of antibiofilm agents and to present selectivity against human cancer cell lines at low concentrations compared to normal cells.
Lestrimelitta limao is a neotropical eusocial bee species found in Brazil and Panama and is part of the Apidae family. It is a species of stingless bees that practices obligate nest robbing. They have never been spotted foraging from flowers, an observation that supports their raiding behavior. Because of their lack of hind corbiculae, they must raid to obtain enough protein in their diet in the form of pollen and nectar. Lestrimelitta limao secrete a lemon-scented alarm allomone, from which they receive their name, in order to conduct successful raids. L. limao are hypothesized to produce poisonous honey that is toxic if consumed by humans. Because robber bees are so rare and difficult to observe, there is a limited scope of information available.