Polyergus rufescens | |
---|---|
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Insecta |
Order: | Hymenoptera |
Family: | Formicidae |
Subfamily: | Formicinae |
Genus: | Polyergus |
Species: | P. rufescens |
Binomial name | |
Polyergus rufescens | |
Synonyms | |
Formica rufescensLatreille, 1798Polyergus testacea(Fabricius, 1804) Contents |
Polyergus rufescens is a species of slave-making ant native to southern Europe and parts of Asia, commonly referred to as the European Amazon ant or as the slave-making ant. It is an obligatory social parasite, unable to feed itself or look after the colony and reliant on ants of another species to undertake these tasks. To replenish these servant ants, it raids nearby ant colonies and carries home pupae and larvae, and these are reared to provide future workers for the colony. A newly mated female P. rufescens needs to make its way into one of these "host" nests, kill the host queen, and be accepted by the host workers in her place.
P. rufescens workers in western and southwestern Europe are dark red, while eastern specimens are more orange-red. Darker ants often have a purplish or brownish tinge to their gasters and appendages. Morphologically, ants of this species are similar to the Mexican Polyergus topoffi , but have narrower heads and petioles and the first tergites of their gasters are more hairy. The total length of this ant is 4.7 to 7 mm (0.19 to 0.28 in). [2]
P. rufescens is native to parts of Europe including Spain, France, the Netherlands, Germany, Switzerland, Austria, Bulgaria, Italy, Croatia, Serbia, and Slovenia. Its range also extends into Asia as far east as the mountains of Kyrgyzstan, Kazakhstan, and western China. Its habitat is typically open, sparse grassland, wherever its host species are to be found. The host species vary in different parts of the range and include F. cunicularia , F. fusca , F. rufibarbis , F. clara , F. gagates , and F. cinerea . The main host species in the eastern part of the range is F. clara and in general, the species chosen is the one most abundant in the locality or that can be raided with the least mortality. [2]
This species is known as the slave-making ant because, like Formica sanguinea , it raids the nests of other species of ant in the subgenus Serviformica and carries their brood back to the dulotic nest (from Greek δοῦλος doulos, "slave"). [1] A mature Polyergus colony always originated as a colony of the slave species (the hosts), and the worker population is maintained by the raiding sorties of the Amazon ants. In the dulotic nest, the Formica workers usually outnumber the Amazon ant population by at least five to one and in general, the behaviour of the mixed colony resembles that of a large colony of the host species. [3] Molecular analysis has shown that although the two slave-making ant genera Polyergus and Rossomyrmex are closely related, they are even more closely related to their respective host species and the enslaving behaviour has evolved independently. [4]
Pierre Huber, the son of the Swiss entomologist François Huber, studied the behaviour of these ants. The P. rufescens workers perform no work apart from nest raiding. [5] So reliant are they on their slaves that without their help, they are incapable of feeding themselves or rearing the young. [6] Huber experimentally put 30 of the slave-making ants in a box with some of their larvae, some pupae, a little soil, and a generous supply of honey. Within two days, half of these ants were dead, presumably of starvation. He then introduced one slave ant into the box. It very soon "established order, formed a chamber in the earth, gathered together the larvae, extricated several young ants that were ready to quit the condition of pupae, and preserved the life of the remaining Amazons." [6]
Winged males and females known as alates emerge from the colonies in summer. Some colonies produce alates of both sexes, and in these the males emerge and fly off some days before the females do. Nuptial flights involving both males and females often occur, but males usually depart from any particular nest first and this prevents inbreeding. Observations on the ground show that the female makes certain movements of her mandibles just before mating, and this is thought to release a sexually attractive pheromone. Some females copulate immediately after the nuptial flight, others mate on the ground near the dulotic nest without taking to the air, and a few mate during the course of a slave raid. The female alates lose their wings within a few minutes of mating, and unless involved in a raid, then hide in the undergrowth near their nests. Others set out alone, probably following the trail of a previous slave raid, and are greeted with hostility at any potential target nest they encounter. The majority join a slave raid within a few days of mating, but only some of these attempt to infiltrate the target colony, others returning home with the raiders. Some winged females also accompany the raiders, and a few of these have been observed returning home carrying a cocoon. [5]
A newly mated female is unable to found a new colony unaided because she is not able to feed herself or care for her first brood. Instead, she enters the nest of another species of ants. She may join a column of raiding ants and use the panic and confusion surrounding their attack on the target colony to infiltrate the nest. She emits a secretion from the Dufour's gland on her abdomen (named after its discoverer, Léon Jean Marie Dufour), which includes a pheromone which subdues the attacked ants and makes them less aggressive. She seeks out the colony's queen and kills her by biting her with her piercing mandibles. With their queen gone, the behaviour of the resident ants changes and their attacks lessen in ferocity and alternate with periods of grooming the new arrival. Within a few hours, the usurping queen is accepted and is surrounded by submissive workers that groom her and feed her. [7]
Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of 22,000 species have been classified. They are easily identified by their geniculate (elbowed) antennae and the distinctive node-like structure that forms their slender waists.
Formica rufibarbis is a European formicine ant of the Formica fusca group. In the classification by Auguste Forel, it is treated in the subgenus Serviformica. F. rufibarbis is subject to a Species Action Plan (SAP) in England, where it is known from only two locations, although it is not considered to be at risk on continental Europe.
Formica rufa, also known as the red wood ant, southern wood ant, or horse ant, is a boreal member of the Formica rufa group of ants, and is the type species for that group, being described already by Linnaeus. It is native to Eurasia, with a recorded distribution stretching from the middle of Scandinavia to the northern Iberia and Anatolia, and from Great Britain to Lake Baikal, with unconfirmed reportings of it also to the Russian Far East. There are claims that it can be found in North America, but this is not confirmed in specialised literature, and no recent publication where North American wood ants are listed mentions it as present, while records from North America are all listed as dubious or unconfirmed in a record compilation. The workers' heads and thoraces are colored red and the abdomen brownish-black, usually with dark patches on the head and promensonotum, although some individuals may be more uniform reddish and even have some red on the part of the gaster facing the body. In order to separate them from closely related species, specimens needs to be inspected under magnification, where difference in hairiness are among the telling characteristics, with Formica rufa being hairier than per example Formica polyctena but less hairy than Formica lugubris. Workers are polymorphic, measuring 4.5–9 mm in length. They have large mandibles, and like many other ant species, they are able to spray formic acid from their abdomens as a defence. Formic acid was first extracted in 1671 by the English naturalist John Ray by distilling a large number of crushed ants of this species. Adult wood ants primarily feed on honeydew from aphids. Some groups form large networks of connected nests with multiple queen colonies, while others have single-queen colonies.
Formica cunicularia is a species of ant found all over Europe. They are especially common in western Europe and southern England, but they can be found from southern Scandinavia to northern Africa and from Portugal to the Urals. In England, Donisthorpe records the species as having occurred as far north as Bewdley in Worcestershire. In Formica cunicularia, the worker is an ashy grey black color and is usually 4.0–6.5 mm long. The males are found to have a uniformly dark body and are 8.0–9.0 mm long. The queen is yellowish red to dark black and is 7.5–9.0 mm.
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 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 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.
Polyergus is a small genus of ants with 14 described species. They are also referred to by the names "slave-raiding ants" and "Amazon ants". They are characterized by their habit of raiding nests for workers.
The banded sugar ant, also known as the sugar ant, is a species of ant native to Australia. A member of the genus Camponotus in the subfamily Formicinae, it was described by German entomologist Wilhelm Ferdinand Erichson in 1842. Its common name refers to the ant's liking for sugar and sweet food, as well as the distinctive orange-brown band that wraps around its gaster.
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.
Harpagoxenus sublaevis is a species of ant in the subfamily Myrmicinae. It is found in Austria, France, Germany, Italy, and Switzerland.
Polyergus breviceps is a species of ant endemic to the United States. It is a social parasite of other ants, namely of Formica gnava but also of Formica occulta and Formica argentea. Polyergus is an inquiline parasite, having lost its ability to take care of its young and themselves. "The workers do not forage for food, feed the young or the queen, or even clean up their own nest". To survive, Polyergus workers raid Formica nests to steal the pupae—which, once hatched, become workers of the mixed nest. This sort of relationship is not unique, of the approximately 8,800 species of ants, at least 200 have evolved some form of symbiotic relationship with one another. What makes Polyergus special is the way a newly mated queen can, all by herself, take over a Formica nest and start a new colony.
Polyergus lucidus is a species of slave-making ant in the subfamily Formicinae endemic to the eastern United States. It is an obligatory social parasite, unable to feed itself or look after its brood and reliant on ants of another species of the genus Formica to undertake these tasks. Parasitic ants are known as "dulotics" and the ants they parasitise are known as "hosts".
Polyergus samurai is a species of slave-making ant in the subfamily Formicinae.
Rossomyrmex is a genus of slave-making ant in the subfamily Formicinae. The genus consists of four species, each with a single host from the genus Proformica, and has a very wide range of distribution from China to southeastern Spain, from huge extended plains to the top of high mountains.
Formica sanguinea, or blood-red ant, is a species of facultative slave-maker ant in the genus Formica characterized by the ability to secrete formic acid. It ranges from Central and Northern Europe through Russia to Japan, China, the Korean Peninsula, Africa and also the United States. This species is coloured red and black with workers up to 7 mm long.
Slave-making ants or slaver ants are brood parasites that capture broods of other ant species to increase the worker force of their colony. After emerging in the slave-maker nest, slave workers work as if they were in their own colony, while parasite workers only concentrate on replenishing the labor force from neighboring host nests, a process called slave raiding.
Polyergus mexicanus is a species of slave-making ant in the subfamily Formicinae. It is the most widely distributed species of Polyergus in North America. It is an obligatory social parasite, unable to feed itself or look after the colony and reliant on ants of another species, Formica, to undertake these tasks. The parasitic ants are known as "dulotics" and the ants they parasitise are known as "hosts".
Formica incerta is a species of ant found in eastern North America. It is the most common species of Formica in many areas, and excavates underground nests with small entrance holes. Its diet includes nectar produced by extrafloral nectaries and honeydew, which it obtains from aphids and treehoppers. It is the main host for the slave-making ant Polyergus lucidus. F. incerta was first described by Italian entomologist Carlo Emery in 1893. Its specific name comes from the Latin incertus meaning "uncertain" and seems particularly apt given the subsequent uncertainty as to the validity of the species and the difficulty in distinguishing this ant from other species living in the same area.
Formica pallidefulva is a species of ant found in North America. It is a red to dark brown ant with a shiny body, and varies in shade across its range. Colonies of this ant are found in a variety of habitats, where they excavate underground nests with galleries and chambers. In some parts of its range, the nests may be raided by slave-making ants, most notably Formica pergandei and Polyergus montivagus.
Camponotus herculeanus is a species of ant in the genus Camponotus, the carpenter ants, occurring in Northern Eurasia, from Norway to Eastern Siberia, and North America. First described as Formica herculeana by Linnaeus in 1758, the species was moved to Camponotus by Mayr in 1861.
This is a glossary of terms used in the descriptions of ants.