Pheidole megacephala | |
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Dorsal view of a minor worker big-headed ant | |
Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Insecta |
Order: | Hymenoptera |
Family: | Formicidae |
Subfamily: | Myrmicinae |
Genus: | Pheidole |
Species: | P. megacephala |
Binomial name | |
Pheidole megacephala (Fabricius, 1793) | |
Synonyms | |
Atta testaceaSmith 1858 Contents |
Pheidole megacephala is a species of ant in the subfamily Myrmicinae. It is commonly known as the big-headed ant in the US and the coastal brown ant in Australia. It is a very successful invasive species and is considered a danger to native ants in Australia [2] and other places. It is regarded as one of the world's worst invasive ant species. [3]
Pheidole megacephala was described from a specimen from the island of Mauritius by the entomologist Johan Christian Fabricius in 1793, although a 1775 record exists for Egypt, under the name Formica edax. [4] Regardless of its African origin, big-headed ants have since spread to many tropical and subtropical parts of the world. [5]
There are two castes (types) of worker ants, the major worker and the minor worker. The common name of bigheaded ant derives from the major worker's disproportionately large head. Major workers are not primarily involved in defence like soldiers of other ant species. They have thick and powerful mandibles which they use to crush seeds and cut up other larger pieces of food for the smaller and more numerous minor workers to transport back to the nest. The major workers are about four millimetres in length, twice as long as the minor workers. The colour of both types varies from yellowish-brown or reddish-brown to nearly black. [6]
The rear half of the head is smooth and glossy and the front half sculptured. The twelve-segmented antennae are curved and have club-like tips. The waist or petiole is two-segmented with the node immediately behind conspicuously swollen. There are a pair of short, upward-facing spines on the waist. The body has sparse, long hairs. [5]
Bigheaded ants nest in colonies underground. Colonies can have several queens [7] and supercolonies can be formed by budding, when a queen and workers leave the original nest and set up a new colony nearby without swarming. [8] In Florida, nuptial flights of winged ants take place during the winter and spring and afterwards, fertilized queens shed their wings and find a suitable site to found a new colony where they start laying eggs. [5] Each queen lays up to 290 eggs per month. The eggs hatch after two to four weeks and the legless white larvae, which are fed by the workers, pupate about a month later. The adult workers emerge ten to twenty days after that. [9]
The minor workers are much more numerous than the soldiers. Trails of ants lead up trunks, along branches and into the canopies of trees and debris-covered foraging tunnels with numerous entrances are created on the surface of the ground. These may be confused with similar tubes built by subterranean termites.
Pheidole megacephala can also live indoors. [10]
The bigheaded ants feed on dead insects, small invertebrates and honeydew excreted by insects such as aphids, soft scale insects, mealybugs, whiteflies and planthoppers. These sap-sucking bugs thrive in the presence of bigheaded ants, being more abundant on plants patrolled by ants than on those not so patrolled. [11] Also, bigheaded ants are predators of the eggs of various species of moths such as the African sugarcane borer, common in sub-Saharan Africa. [12] Green scale, Coccus viridis, flourished when bigheaded ants protected their food source by removing predators such as lady beetle larvae and lepidopteran larvae. [13]
Foraging ants will alert others to new food sources. Honeydew is ingested but other foodstuffs are carried back to the nest by both major and minor workers who may transfer items of food between themselves. Anything too big to be moved may be dissected before being brought back to the nest. [5]
Bigheaded ants are a threat to biodiversity through the displacement of native invertebrate fauna and is a pest of agriculture through harvesting seeds and harbouring insects on crops. They are also known to chew on irrigation and telephone cabling as well as electrical wires. [3] In a scientific study, Bigheaded ants are blamed for influencing the entire food chain in the Kenya savannah. [14]
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.
The yellow crazy ant, also known as the long-legged ant or Maldive ant, is a species of ant, thought to be native to West Africa or Asia. They have been accidentally introduced to numerous places in the world's tropics.
Pheidole is a genus of ants that belongs to the ant subfamily Myrmicinae. The genus is widespread and ecologically dominant. It probably includes more than 1000 species. The genus first evolved in the Americas, eventually spreading across the globe.
Weaver ants or green ants are eusocial insects of the Hymenoptera family Formicidae belonging to the tribe Oecophyllini. Weaver ants live in trees and are known for their unique nest building behaviour where workers construct nests by weaving together leaves using larval silk. Colonies can be extremely large consisting of more than a hundred nests spanning numerous trees and containing more than half a million workers. Like many other ant species, weaver ants prey on small insects and supplement their diet with carbohydrate-rich honeydew excreted by scale insects (Hemiptera). Weaver ant workers exhibit a clear bimodal size distribution, with almost no overlap between the size of the minor and major workers. The major workers are approximately 8–10 mm (0.31–0.39 in) in length and the minors approximately half the length of the majors. Major workers forage, defend, maintain, and expand the colony whereas minor workers tend to stay within the nests where they care for the brood and 'milk' scale insects in or close to the nests.
Oecophylla smaragdina is a species of arboreal ant found in tropical Asia and Australia. These ants form colonies with multiple nests in trees, each nest being made of leaves stitched together using the silk produced by the ant larvae: hence the name 'oecophylla' [Greek for 'leaf-house'].
Formica fusca is a black-colored ant commonly found throughout Europe as well as parts of southern Asia and Africa. It has the common names silky ant or dusky ant. The range within the palaearctic region extends from Portugal in the west to Japan in the east and from Italy in the south to Fennoscandia in the north. Populations from North America have been split off as a separate species, Formica subaenescens. F. fusca nests are usually found in rotten tree stumps or under stones in clearcut areas and along woodland borders and hedgerows. The species also often occurs in urban areas, feeding on honeydew secreted by the aphids found on weeds.
Technomyrmex albipes, commonly known as the white-footed ant, is a species of ant first described in 1861 from Sulawesi, Indonesia by the British entomologist Frederick Smith. Invasive pest ants in Florida, previously identified as T. albipes, have now been separated as Technomyrmex difficilis, both forming part of a species complex with a worldwide distribution.
Ochetellus glaber is a species of ant native to Australia. A member of the genus Ochetellus in the subfamily Dolichoderinae, it was described by Austrian entomologist Gustav Mayr in 1862. Aside from Australia, O. glaber has been introduced to a number of countries, including China, India, Japan, New Zealand, the Philippines and the United States, where it has established itself in Hawaii and Florida. It has been found on Lord Howe Island, New Caledonia, Norfolk Island, Réunion, New Zealand, and the Solomon Islands. Compared with other ants, O. glaber is a small species, with workers measuring 2–3 mm (0.079–0.118 in). Males are the smallest at 1.6 mm (0.063 in), while the queens measure 5.2–5.5 mm (0.20–0.22 in). The ant's colour ranges from brown to black.
Coccus viridis is a soft scale insect in the family Coccidae with a wide host range. It is commonly known as green scale or sometimes coffee green scale because it is a major pest of coffee crops throughout the world.
Oecophylla longinoda is a species of arboreal ant found in the forested regions of tropical Africa. They are one of only two extant species of the genus Oecophylla, the other being O. smaragdina. They make nests in trees made of leaves stitched together using the silk produced by their larvae.
Doleromyrma darwiniana is a species of ant in the genus Doleromyrma. Described by Forel in 1907, the species is endemic to Australia and introduced to New Zealand, and it nests in soil or under stones and logs. The organism grows to a length between 2.0 and 3.0 millimeters. This species of ant maintains small colony sizes and it "prefers protein food." The species is also known by some sources as the "brown house ant" and "Darwin's ant". The species is considered a "minor urban pest" in New South Wales.
Crematogaster peringueyi is a southern African arboreal species of ant. They are commonly known as the black cocktail ant or swartwipgatmier (Afrikaans) for their colour and habit of arching their abdomens when alarmed.
Trichomyrmex destructor is a species of ant in the subfamily Myrmicinae. Its common names include destructive trailing ant or Singapore ant. It is a pest species in urban areas, known for causing costly damage to structures, vehicles, and electronic devices with its chewing activity. In 2015, the species was moved from the genus Monomorium to the revised genus Trichomyrmex.
Coccus hesperidum is a soft scale insect in the family Coccidae with a wide host range. It is commonly known as brown soft scale. It has a cosmopolitan distribution and feeds on many different host plants. It is an agricultural pest, particularly of citrus and commercial greenhouse crops.
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.
Plagiolepis alluaudi, the little yellow ant, is a species of Plagiolepis. The species is native to Madagascar, an island off the coast of East Africa. It is known to be a widespread invasive species. In an effort to distinguish its name from other small and yellow species of ant it may be called Alluaud's little yellow ant, after Charles A. Alluaud.
Chilocorus cacti, known generally as the cactus lady beetle or the twice-stabbed cactus lady beetle, is a species of lady beetle in the family Coccinellidae. It is native to the Caribbean region, North America, Central America, and South America. The adults and larvae feed on scale insects and attempts have been made to use it for biological pest control.
Toumeyella parvicornis is a soft scale insect in the family Coccidae with a wide host range. It is commonly known as pine tortoise scale because of the characteristic appearance of the mature females, which look like tiny tortoises 4–5mm long.
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.
There are 803 species of ants currently known in the Democratic Republic of the Congo. Unusually, there are no known introduced species in this region. The majority of species occur in the Congolese rainforest and Central Congolian lowland forests.