Formica exsecta | |
---|---|
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Insecta |
Order: | Hymenoptera |
Family: | Formicidae |
Subfamily: | Formicinae |
Genus: | Formica |
Species: | F. exsecta |
Binomial name | |
Formica exsecta Nylander, 1846 | |
Formica exsecta (the narrow-headed ant or excised wood ant) is a species of ant found from Western Europe to Asia.
A rare formicine ant with a deeply excised head, F. exsecta forms small mounds up to around a foot in height consisting of much finer material than that used by "true" wood ants of the F. rufa group.
An interesting feature of F. exsecta is that it occurs in two distinct social forms: either a monogyne form where the colony has a single egg-laying queen, or a polygyne form where many egg-laying queens are part of the same colony.
F. exsecta is placed in the Coptoformica subgenus within the genus and is closely related to Formica exsectoides , an American species. Both species may form vast colony networks. The largest known polydomous system of F. exsecta consists of 3,350 nests dispersed over about 22 ha in Transylvania, Romania. [1] [2]
In Great Britain, F. exsecta can be found only in a few scattered heathland locations in South West England — principally Chudleigh Knighton Heath and nearby Bovey Heath, which are both managed by the Devon Wildlife Trust, and in the central Scottish Highlands (including Rannoch Moor). [3] A population centre previously existed in the New Forest, and such eminent myrmecologists as Horace Donisthorpe recorded this species there and in Parkhurst Forest on the Isle of Wight in the last century, but this seems to have declined considerably over the past few decades, and recent searches in such locations have failed to find any trace of colonies. The narrow-headed ant is currently one of the target species in the Back from the Brink project, which aims to extend its range in England. [4]
F. exsecta has also been found in forests in Sweden, Finland, Germany, Tibet, and China.
F. exsecta is a eusocial species, displaying a dominance hierarchy among its individual colony members. Amongst the narrow-headed ant species, the two different types of colony structure are: monogyny, one queen per colony, and polygyny, more than one queen per colony. [5] Most commonly, one of these two different types is prevalent within a population. These two types of colonies differ not only in the queen's mating system, but also in the organization of types of offspring and its hierarchy system. For a polygynous colony to thrive, it must adjust its sex allocation practices contingent on the abundance of resources. Colonies produce a greater percentage of male offspring when restraint on resource availability exists, as well as when the colony has a larger number of queens. [6] The opposite scenario is also found to be true. More female offspring are produced when an abundance of resources exists, as well as when the colony has a smaller number of queens. On average, a colony's sex ratio is estimated to be 5.8% female, or one female for every 17.2 male offspring. [7] This heavily male offspring-based sex ratio displays an obvious deviation from Fisher's theory of 1:1 sex ratio.
In colonies in which the male offspring are favored, workers tend to execute most of the female gynes. In contrast, colonies where an excess of female gynes is produced, which is more than necessary for the simple act of queen replacement, they are all accepted into the colony to eliminate the possibility of parasitism by unrelated queens from neighboring populations. [8]
In monogynous colonies, a significant amount of inbreeding is found. Inbreeding coefficients were found positive for the workers of these colonies. No inbreeding was found between mother queens. Procreation between related individuals of the colony can be further explained by the queen-male relatedness coefficient of 0.23, found by experiments from Liselotte Sundström. [5] Male offspring that were reared in an inbred colony tended to be smaller in mass. Gynes reared in inbred colony display no difference in mass compared to those in noninbred colonies. This result reflects a trade-off between the quantity of offspring and their reproductive potential. Gynes' reproductive success is more dependent on their mass than that of a male. [9]
In single-queen colonies, the level of queen homozygosity is negatively associated with colony age. [10] Reduced colony survival appears to be due to reduced queen lifespan resulting from queen homozygosity.
Worker homozygosity appeared to affect reproductive allocation, with higher homozygosity being associated with less resources being allocated to the sexual brood and more to worker production. [10]
F. exsecta, much like other insects in the order Hymenoptera, have a haplodiploid sex determination system. An unusual 0.75 relatedness coefficient between full haplodiploid sisters is one of the main contributors to the frequency of evolution of eusocial species. [11] The queen's eggs that are fertilized grow into diploid daughters, which contain two pairs of chromosomes, whereas unfertilized eggs produce haploid males, which only contain the queen's chromosomes. The voluntary fertilization of eggs is done by the egg-laying mother. Therefore, ideally, the queen's best reproductive interest is to lay a larger quantity of eggs or increase the number of eggs that produce individuals that can reproduce themselves. However, female-rich colonies emphasized the production of workers rather than gynes. [12]
Hymenoptera is a large order of insects, comprising the sawflies, wasps, bees, and ants. Over 150,000 living species of Hymenoptera have been described, in addition to over 2,000 extinct ones. Many of the species are parasitic. Females typically have a special ovipositor for inserting eggs into hosts or places that are otherwise inaccessible. This ovipositor is often modified into a stinger. The young develop through holometabolism — that is, they have a wormlike larval stage and an inactive pupal stage before they reach adulthood.
Formica is a genus of ants of the family Formicidae, including species commonly known as wood ants, mound ants, thatching ants, and field ants. Formica is the type genus of the Formicidae, and of the subfamily Formicinae. The type species of genus Formica is the European red wood ant Formica rufa. Ants of this genus tend to be between 4 and 8 mm long. Ants belonging to the Formica genus possess a single knob or bump located between their thorax and abdomen. These ants primarily feed on honeydew, a sugary liquid produced by aphids. Formica ants appear to take on a shepherding role with smaller aphids, relocating them to different parts of plants to ensure a continuous food source for the aphids. By doing so, the ants can establish a relatively sustainable honeydew supply for both themselves and their colony.
Thelytoky is a type of parthenogenesis and is the absence of mating and subsequent production of all female diploid offspring as for example in aphids. Thelytokous parthenogenesis is rare among animals and reported in about 1,500 species, about 1 in 1000 of described animal species, according to a 1984 study. It is more common in invertebrates, like arthropods, but it can occur in vertebrates, including salamanders, fish, and reptiles such as some whiptail lizards.
Haplodiploidy is a sex-determination system in which males develop from unfertilized eggs and are haploid, and females develop from fertilized eggs and are diploid. Haplodiploidy is sometimes called arrhenotoky.
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.
A queen ant is an adult, reproducing female ant in an ant colony; she is usually the mother of all the other ants in that colony. Some female ants, such as the Cataglyphis, do not need to mate to produce offspring, reproducing through asexual parthenogenesis or cloning, and all of those offspring will be female. Others, like those in the genus Crematogaster, mate in a nuptial flight. Queen offspring ants among most species develop from larvae specially fed in order to become sexually mature.
Formica polyctena is a species of European red wood ant in the genus Formica and large family Formicidae. The species was first described by Arnold Förster in 1850. The latin species name polyctena is from Greek and literally means 'many cattle', referring to the species' habit of farming aphids for honeydew food. It is found in many European countries. It is a eusocial species, that has a distinct caste system of sterile workers and a very small reproductive caste. The ants have a genetic based cue that allow them to identify which other ants are members of their nest and which are foreign individuals. When facing these types of foreign invaders the F. polyctena has a system to activate an alarm. It can release pheromones which can trigger an alarm response in other nearby ants.
Eusociality is the highest level of organization of sociality. It 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 behaviors characteristic of individuals in another caste. Eusocial colonies can be viewed as superorganisms.
Polistes metricus is a wasp native to North America. In the United States, it ranges throughout the southern Midwest, the South, and as far northeast as New York, but has recently been spotted in southwest Ontario. A single female specimen has also been reported from Dryden, Maine. Polistes metricus is dark colored, with yellow tarsi and black tibia. Nests of Polistes metricus can be found attached to the sides of buildings, trees, and shrubbery.
Within the insect order Hymenoptera, the Halictinae are the largest, most diverse, and most recently diverged of the four halictid subfamilies. They comprise over 2400 bee species belonging to the five taxonomic tribes Augochlorini, Thrinchostomini, Caenohalictini, Sphecodini, and Halictini, which some entomologists alternatively organize into the two tribes Augochlorini and Halictini.
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.
Leptothorax acervorum is a small brown to yellow ant in the subfamily Myrmicinae. It was first described by Johan Christian Fabricius in 1793. L. acervorum is vastly distributed across the globe, most commonly found in the coniferous forests of Central, Western and Northern Europe. The morphology of L. acervorum is extremely similar to that of other Leptothorax ants. The difference arises in the two-toned appearance of L. acervorum, with the head and metasoma being darker than the mesosoma segment of the body, and hair across its body. Following Bergmann's rule—unusually, for ectothermic animals—body size increases with latitude.
Formica truncorum is a species of wood ant from the genus Formica. It is distributed across a variety of locations worldwide, including central Europe and Japan. Workers can range from 3.5 to 9.0mm and are uniquely characterized by small hairs covering their entire bodies. Like all other ants, F. truncorum is eusocial and demonstrates many cooperative behaviors that are unique to its order. Colonies are either monogynous, with one queen, or polygynous, with many queens, and these two types of colonies differ in many characteristics.
Halictus ligatus is a species of sweat bee from the family Halictidae, among the species that mine or burrow into the ground to create their nests. H. ligatus, like Lasioglossum zephyrus, is a primitively eusocial bee species, in which aggression is one of the most influential behaviors for establishing hierarchy within the colony, and H. ligatus exhibits both reproductive division of labor and overlapping generations.
Belonogaster petiolata is a species of primitively eusocial wasp that dwells in southern Africa, in temperate or subhumid climate zones. This wasp species has a strong presence in South Africa and has also been seen in northern Johannesburg. Many colonies can be found in caves. The Sterkfontein Caves in South Africa, for example, contain large populations of B. petiolata.
Polistes biglumis is a species of social wasp within Polistes, the most common genus of paper wasp. It is distinguished mainly by its tendency to reside in montane climates in meadows or alpine areas. Selection pressure from the wasp's environment has led to several idiosyncrasies of its behavior and lifecycle with respect to its relative species in the genus Polistes. It alone among paper wasps is often polyandrous. In addition, it has a truncated nesting season that gives rise to unique competitive dynamics among females of the species. P. biglumis wasps use an odor-based recognition system that is the basis for all wasp-to-wasp interaction of the species. The wasp's lifecycle is highly intertwined with that of Polistes atrimandibularis, an obligate social parasite wasp that frequently invades the combs of P. biglumis wasps.
This is a glossary of terms used in the descriptions of ants.
Plebeia remota is a species of stingless bee that is in the family Apidae and tribe Meliponini. Bees of the species are normally found in a few states in southern Brazil and their nests can be found in tree cavities. Depending on the region, P. remota may have a different morphology and exhibit different behaviors. The bee's diet consists of nectar and pollen that are collected intensely from a few sources. Researchers have conducted a multitude of studies analyzing the changes that occur in the colony during reproductive diapause and what happens during the provisioning and oviposition process or POP.
Liselotte Sundström is a Finnish zoologist. She is professor emerita of evolutionary biology at the University of Helsinki.
An ant supercolony is an exceptionally large ant colony, consisting of a high number of spatially separated but socially connected nests of a single ant species, spread over a large area without territorial borders. Supercolonies are typically polygynous, containing many egg-laying females. Workers and queens from different nests within the same supercolony can freely move among the nests, and all workers cooperate indiscriminately with each other in collecting food and care of the brood, and show no apparent mutual aggressive behavior.
{{cite book}}
: CS1 maint: multiple names: authors list (link)