Formica obscuripes

Last updated

Formica obscuripes
Formica obscuripes casent0005389 profile 1.jpg
F. obscuripes worker
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Formicinae
Genus: Formica
Species:
F. obscuripes
Binomial name
Formica obscuripes
Forel, 1886

Formica obscuripes, the western thatching ant, is a species of ant in the family Formicidae. It is native to North America. It produces large mounds covered by small pieces of plant material. [1] The number of adult workers per colony may be as high as 40,000. [2] F. obscuripes feeds upon a number of insect species, consumes nectar from homopterous insects they tend, and occasionally eats plant tissue. [1]

Contents

Biology

Colonies

mound Formica obscuripes 26474.JPG
mound
mound (close-up) Formica obscuripes mound.JPG
mound (close-up)
mound with workers Formica obscuripes Apr 2016.jpg
mound with workers

F. obscuripes creates distinct, dome-shaped mounds composed of varying materials found in the nest's surrounding environment. This composition is primarily vegetation and is commonly called "thatch". The mounds are typically constructed in areas devoid of cover to expose the nest to sunlight. The size of these mounds is highly variable and is mostly determined by the age and health of the colony. The height ranges from 1 to 18 inches (15–45 cm), although nests of larger heights are not uncommon, and can extend down to 4 ft (1.2 m) in the ground, with chambers present in both the thatched mound and the soil. The condition of the thatched mound is in a constant state of change due to activities by the ants and changes in the environment. [3] To prevent plants from shading the nest, the ants may chew off the bark at the base of plants growing on or nearby the mound. Formic acid is then sprayed into the open layer eventually killing and felling the plants. [4]

In the Blue Mountains of Oregon, F. obscuripes has demonstrated the capacity for polydomy. A supercolony in a four-hectare (9.9 acre) study area near Lehman Hot Springs consisted of 210 active nests with an estimated population in excess of 56 million ants. [5]

Chemistry

The poison sprayed by Formica obscuripes consists of formic acid, eight straight-chain alkanes, a branched-chain alkane and five alkenes. The major component, formic acid, has been found to vary from 8 to 96% and average 73% of the volatiles in the secretion. A variation was also seen with the second most abundant compound, undecane, which ranged from 3 to 63% of the sprayed secretion and averaged 19%. [6]

Distribution

F. obscuripes is found in a variety of habitats in North America, particularly the United States of America. Most specimens are collected from the Midwest and between the Rocky Mountains and the American west coast. [7] Populations in the Pacific Northwest may represent a distinct species, Formica planipilis , [8] and have been described by hobbyists as typically producing larger colonies and mounds than populations elsewhere, though this has not been confirmed. Pacific Northwest populations are additionally distinguished by the unique coloration of the gynes, which sport entirely black bodies with red heads.

Related Research Articles

<span class="mw-page-title-main">Ant</span> Family of insects

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.

<i>Formica exsecta</i> Species of ant

Formica exsecta is a species of ant found from Western Europe to Asia.

<i>Formica</i> Genus of ants

Formica is a genus of ants of the subfamily Formicinae, 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.

<i>Formica rufa</i> species group Group of ants

The Formica rufa group is a subgeneric group within the genus Formica, first proposed by William Morton Wheeler. This group contains the mound-building species of Formica commonly termed "wood ants" or "thatch-mound ants", which build prominent nests consisting of a mound of grass, litter, or conifer needles. The species Formica rufa or the red wood ant is the type species of this subgroup.

<i>Formica rufa</i> Species of ant

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.

<i>Formica cunicularia</i> Species of ant

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.

<span class="mw-page-title-main">Ant colony</span> Underground lair where ants live, eat, and tend eggs

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.

<span class="mw-page-title-main">Banded sugar ant</span> Species of carpenter ant (Camponotus consobrinus)

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.

<i>Iridomyrmex</i> Genus of ants

Iridomyrmex is a genus of ants called rainbow ants first described by Austrian entomologist Gustav Mayr in 1862. He placed the genus in the subfamily Dolichoderinae of the family Formicidae. It has 79 described species and five fossil species. Most of these ants are native to Australia; others are found in Asia and Oceania, and they have been introduced to Brazil, New Zealand, and the United Arab Emirates. Fossil species are known from China, France, and the United States.

<i>Formica lugubris</i> Species of ant

Formica lugubris, also known as the hairy wood ant is commonly found in wooded upland areas across northern Eurasia. Colonies construct large thatched mound nests occupied by thousands of workers, and one or more queens. Workers look similar to other species of wood ants, but Formica lugubris workers can be identified by a fringe of hairs that reaches down to their eyes and prominent hairs between the facets of their compound eyes. Workers can reach sizes of up to 9 mm long; queens are larger, reaching 12 mm long.

<i>Formica polyctena</i> Species of ant

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.

<i>Formica pratensis</i> Species of ant

Formica pratensis, the black-backed meadow ant, is a species of European red wood ant in the family Formicidae.

<i>Formica sanguinea</i> Species of ant

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.

<i>Camponotus vagus</i> Species of carpenter ant

Camponotus vagus is a species of large, black, Palaearctic carpenter ant with a wide range that includes much of Europe, a large area of Asia, and part of Africa.

<span class="mw-page-title-main">Argentine ant</span> Species of ant

The Argentine ant is an ant native to northern Argentina, Uruguay, Paraguay, Bolivia and southern Brazil. This invasive species was inadvertently introduced by humans on a global scale and has become established in many Mediterranean climate areas, including South Africa, New Zealand, Japan, Easter Island, Australia, the Azores, Europe, Hawaii, and the continental United States. Argentine ants are significant pests within agricultural and urban settings, and are documented to cause substantial harm to communities of native arthropods, vertebrates, and plants within their invaded range.

<i>Forelius pruinosus</i> Species of ant

Forelius pruinosus, commonly known as the high noon ant, is a species of ant in the genus Forelius. Described by Roger in 1863, the species is endemic to North America and has been recently observed in Latin America.

<i>Formica montana</i> Species of ant

Formica montana is an ant in the genus Formica in the family Formicidae. A common name for F. montana is "prairie mound ant".

<span class="mw-page-title-main">Ant supercolony</span> Exceptionally large ant colony

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.

<i>Formica paralugubris</i> Species of ant

Formica paralugubris is a species of ant. It is a member of the Formica rufa species group native to the Alps in the Palearctic realm. It is a cryptic species, often miscategorized as Formica lugubris due to morphological similarities. The two species are capable of differentiating one another, however; F. paralugubris ants react aggressively towards F. lugubris ants.Formica paralugubris differs in its organization as a supercolony. It has been introduced into North America with the import of pine trees. It does not exhibit characteristics found in other invasive species due to its limited native range.

References

  1. 1 2 Heikkinen, M. W. (1999). "Negative effects of the western thatching ant (Formica obscuripes) on spiders (Araneae) inhabiting big sagebrush (Artemisia tridentata)". Great Basin Naturalist. 59 (4): 380–383.
  2. Capinera, J. L. (2008). Encyclopedia of Entomology, Volume 3. Springer. p. 4215. ISBN   978-1-4020-6242-1.
  3. Weber, N (1935). "The Biology of the Thatching Ant, Formica rufa obscuripes Forel, in North Dakota" (PDF). Ecological Monographs. 5 (2): 165–206. Bibcode:1935EcoM....5..165W. doi:10.2307/1948522. JSTOR   1948522.
  4. Cole, S.C. Jr. (1932). "The Thatching Ant, Formica obscuripes Forel" (PDF). Psyche: A Journal of Entomology. 39 (1–2): 30–33. doi: 10.1155/1932/61715 .
  5. J. McIver, T. Torgersen and N. Cimon. A supercolony of the thatch ant Formica obscuripes Forel (Hymenoptera:Formicidae) from the Blue Mountains of Oregon. Northwest Science vol 71 issue 1, Feb 1997 (full-text)
  6. Faith G. W.; Sollers B. G.; D Feeny R. M.; Wood W. J. L.; Wood W. F. (2011). "Chemical analysis of the defensive secretion from the western thatching ant, Formica obscuripes". Journal of Undergraduate Chemistry Research. 10: 15–17.
  7. "Species: Formica obscuripes". AntWeb. Version 8.108. California Academy of Science. 2024. Retrieved 18 August 2024.
  8. Stockan, Jenni A.; Robinson, Elva J. H.; Trager, James C.; Yao, Izumi; Seifert, Bernhard (June 2016). Wood Ant Ecology and Conservation. Cambridge University Press. doi:10.1017/CBO9781107261402. ISBN   9781107261402.