Anoplolepis gracilipes (Smith 1857)

La formiga boja groga (Anoplolepis gracilipes) és una espècie de formiga de la subfamília Formicinae, comunament groga, associada a l'ésser humà com a modificadora de l'ambient, ja siguin àrees agrícoles o zones urbanes. En algunes illes tropicals inclosa l'illa de Nadal, ha adquirit grans densitats escalabornant els invertebrats natius i algunes poblacions de vertebrats, especialment alguns ocells. En alguns casos, ha resultat en el canvi de composició forestal i la disminució dels cicles nutritius; això afecta la fauna nativa per la competència dels recursos de menjar. En minvar la biodiversitat, indirectament amenaça els sectors turístics. Aquesta relació amb diversos insectes productors de mel, afecta la flora nativa i causa danys significatius a les plantes i pèrdues econòmiques en sistemes agrícoles.

Gelbe Spinnerameisen auf Hawaii

Die Gelbe Spinnerameise (Anoplolepis gracilipes, englisch Yellow Crazy Ant) ist eine Ameisenart, die unbeabsichtigt im Norden Australiens (erstmals 1978 im tropischen Regenwald der Atherton Tablelands), auf der Weihnachtsinsel im Indischen Ozean und in anderen tropischen Lebensräumen weltweit eingeführt wurde. Dort richtet die Art als Neozoon beträchtlichen Schaden in bestehenden Ökosystemen an, indem sie die einheimische Biodiversität reduziert und eine Bedrohung für ansässige gefährdete Arten darstellt. Aus diesem Grund wird die Ameise in der Global Invasive Species Database zu den schädlichsten invasiven Neobiota weltweit gezählt.^[1] Die ursprüngliche Heimat der Tiere ist unbekannt, man nimmt an, dass sie in Westafrika, Indien oder China liegt.

Auswirkungen als Neozoon auf der Weihnachtsinsel

Besonders auf der Weihnachtsinsel stellen die Ameisen eine Bedrohung für die heimische Flora und Fauna dar. Hier haben sie ihr Verhalten dahingehend geändert, dass sie keine Einzelkolonien mehr mit einzelnen Königinnen, sondern sogenannte Superkolonien mit mehreren kooperierenden Königinnen bilden. Die Tiere sind sehr aggressiv und mit Hilfe der Ameisensäure auch in der Lage, größere Tiere zu überwältigen. Sie greifen entsprechend kleine Reptilien ebenso an wie Palmendiebe und sind verantwortlich für den Tod von 10 bis 20 Millionen Weihnachtsinsel-Krabben. Durch das Fehlen der Weihnachtsinsel-Krabben können Sämlinge gedeihen, die von ihnen normalerweise unter Kontrolle gehalten werden, wodurch sich die Flora der Wälder zugunsten dieser Pflanzen verschiebt.

Ein weiteres Phänomen, das bei dieser Ameisenart zu beobachten ist, ist die eigene Züchtung von Schildläusen, die ihrerseits den Ameisen durch Produktion des sogenannten Honigtaus Nährstoffe liefern, und die im Gegenzug von den Ameisen in neue Pflanzenbestände transportiert werden. Durch dieses symbiotische Verhältnis tritt ein Ungleichgewicht im Ökosystem auf, vor allem, wenn der abgesonderte Honigtau nicht von den Ameisen abgeerntet wird, sondern auf die darunterliegenden Pflanzenteile fällt und sich dort als eine klebrige, lichtundurchlässige Masse absetzt. Diese Masse verhindert die Photosynthese der betroffenen Pflanze und verursacht somit weitere Waldschäden, insbesondere auf der Weihnachtsinsel.

Auch der Weißbauch-Fregattvogel (Fregata andrewsi) sowie der Graufußtölpel (Papasula abbottii) sind durch diese Art bedroht. Wissenschaftler befürchten, dass sich die Bestände um etwa 80 Prozent reduzieren werden, da die Ameisen die Jungtiere dieser Vögel töten.

Lange Zeit gab es keine effektiven Gegenmittel gegen die Ameisen. Auch durch hochdosierte Insektizide konnten keine nennenswerten Erfolge erzielt werden. Bei einem 2009 durchgeführten Versuch mit niedrig dosierten Fipronil-Ködern konnte allerdings die Populationsdichte einer Superkolonie um 99 % reduziert werden. Die australische Regierung hat 4 Millionen AUD zur Erforschung weiterer Abwehrmaßnahmen bereitgestellt, die Studien werden unter anderem an der La Trobe University und der Monash University durchgeführt.^[2]

Als Neozoon auf Sulawesi

Findet die Sulawesi-Kröte bei der Nahrungssuche die Gelbe Spinnerameise, ernährt sie sich hauptsächlich von ihr. Dies ist bemerkenswert, weil die Gelbe Spinnerameise Ende der 1970er Jahre als Neozoon nach Sulawesi gelangte. Durch ihr Fraßverhalten nehmen die Kröten positiven Einfluss auf die Population der einheimischen Ameisenarten und damit indirekt eventuell auch auf die Kontrolle von Krankheiten unter den Kakaobäumen.^[3]

Namensgebung

Der englische Name Crazy Ants leitet sich von der Fortbewegung der Tiere ab. Diese bewegen sich sehr rasch vorwärts und schlagen dabei ständig neue Richtungen ein – vor allem, wenn sie gestört werden.

Literatur

• Alfred Buschinger: Risiken und Gefahren zunehmenden internationalen Handels mit Ameisen zu Privat-Haltungszwecken (Hymenoptera: Formicidae). In: Myrmecologische Nachrichten. Band 6, 2004, ISSN 1994-4136, S. 79–82 (online [PDF; 148 kB] Registrierung erforderlich).

Einzelnachweise

1. ↑ 100 of the World’s Worst Invasive Alien Species. 6. Anoplolepis gracilipes. In: Global Invasive Species Database. International Union for Conservation of Nature and Natural Resources (IUCN), abgerufen am 15. September 2016 (englisch).
2. ↑ Conservation projects. Yellow crazy ants. In: www.environment.gov.au. Australian Government – Department of the Environment and Energy, abgerufen am 15. September 2016 (englisch).
3. ↑ Thomas C. Wanger u. a: Endemic predators, invasive prey and native diversity. In: Proceedings of the Royal Society B – Biological Sciences. 8. September 2010, doi:10.1098/rspb.2010.1512 (englisch).

The yellow crazy ant (Anoplolepis gracilipes), 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.^[2][3]

The yellow crazy ant has colloquially been given the modifier "crazy" on account of the ant's erratic movements when disturbed. Its long legs and antennae make it one of the largest invasive ant species in the world.^[1][4]

Like several other invasive ants, such as the red imported fire ant (Solenopsis invicta), the big-headed ant (Pheidole megacephala), the little fire ant (Wasmannia auropunctata), and the Argentine ant (Linepithema humile), the yellow crazy ant is a "tramp ant", a species that easily becomes established and dominant in new habitat due to traits such as aggression toward other ant species, little aggression toward members of its own species, efficient recruitment, and large colony size.^[5]

It is on a list of "one hundred of the world's worst invasive species" formulated by the International Union for Conservation of Nature (IUCN),^[6] having invaded ecosystems from Hawaii to the Seychelles, and formed supercolonies on Christmas Island in the Indian Ocean.^[7]

In 2023, a scientific article postulated a unique reproductive cycle for A. gracilipes, suggesting that males are obligate chimeras.^[8]

Physiology

Anoplolepis gracilipes is a relatively large, yellow to orange ant with long legs, large eyes and extremely long antennal scapes.

Although A. gracilipes is the only invasive species in the genus Anoplolepis, there are several other genera for which it can be mistaken. Both Leptomyrmex and Oecophylla can be confused with Anoplolepis because of their similar sizes and very long limbs. Anoplolepis can be distinguished from Leptomyrmex by the presence of an acidopore, while Anoplolepis can be distinguished from Oecophylla by the more compact petiole. Although both of these genera occur in the Pacific, neither contain any invasive species.

Several species of invasive ants belonging to the genera Camponotus and Paratrechina can appear similar to A. gracilipes. Although several invasive species of Pheidole can also be slender-bodied with long legs and long antennal scapes, they can be separated from A. gracilipes by their two-segmented waists.

A. gracilipes is widespread across the tropics, and populations are especially dense in the Pacific region. The species is most infamous for causing the ecological "meltdown" of Christmas Island.^[9][7] Although widespread across the Pacific, A. gracilipes can cause significant damage to native biological diversity. Strong quarantine measures are encouraged to keep it from spreading to new localities.

Geographical range and dispersal

A dead gecko being dragged by yellow crazy ants in India

The yellow crazy ant's natural habitats are the moist tropical lowlands of Southeast Asia, and surrounding areas and islands in the Indian and Pacific Oceans.^[10] It has been introduced into a wide range of tropical and subtropical environments including northern Australia, some of the Caribbean islands, some Indian Ocean islands (Seychelles, Madagascar, Mauritius, Réunion, the Cocos Islands and the Christmas Islands)^[7] and some Pacific islands (New Caledonia, Hawaii, French Polynesia, Okinawa, Vanuatu, Micronesia, Johnston Atoll, and the Galapagos archipelago).^[11][12] The species has been known to occupy such agricultural systems as cinnamon, citrus, coffee and coconut plantations. Because yellow crazy ants have generalized nesting habits, they are able to disperse via trucks, boats and other forms of human transport.^[1]

Crazy ant colonies naturally disperse through "budding", i.e. when mated queens and workers leave the nest to establish a new one, and only rarely through flight via female winged reproductive forms. Generally, colonies that disperse through budding have a lower rate of dispersal, requiring human intervention to reach distant areas. It has been recorded that A. gracilipes moves as much as 400 m (1,300 ft) a year in the Seychelles.^[11] A survey on Christmas Island, however, yielded an average spreading speed of 3 meters (9.8 ft) per day, the equivalent of one kilometer (0.6 mile) per year.^[13]

Diet

A. gracilipes (yellow crazy ants) moving dead Blattidae sp. (cockroach) toward their nest in Pohnpei, Federated States of Micronesia

A. gracilipes has been described as a "scavenging predator" exhibiting a broad diet, a characteristic of many invasive species. It consumes a wide variety of foods, including grains, seeds, arthropods, and decaying matter such as vertebrate corpses. They have been reported to attack and dismember invertebrates such as small isopods, myriapods, molluscs, arachnids, land crabs, earthworms and insects.^[13]

Like all ants, A. gracilipes requires a protein-rich food source for the queen to lay eggs and carbohydrates as energy for the workers. They get their carbohydrates from plant nectar and honeydew producing insects, especially scale insects, aphids, and other Sternorrhyncha. Studies indicate that crazy ants rely so much on scale insects that a scarcity of them can actually limit ant population growth.^[11]

Reproduction

Similar to other ants, the queen produces eggs which are fertilized by male sperm that are stored in sperm stores. When an egg is fertilized, there are three distinct events that can happen: (i) the resulting diploid organism develops into a queen if the egg is fertilized by an R sperm or (ii) into an infertile diploid worker if the egg is fertilized by a W sperm. However, a third outcome has been described in a 2023 scientific study: (iii) the egg is fertilized by a W sperm but the parental nuclei bypasses the fusion of the two gametes and divide separately within the same egg, leading to a haploid male that is chimeric with a portion of cells carrying the W genome and a portion of cells carrying the R genome.^[8] Interestingly, not all tissues have equal proportions of each cell line, with sperm cells mostly carrying the W genome and thus providing the W alleles with a fitness advantage.^[8] This is the first known case of obligate chimerism in animals.^[14][15]

Mutualism

Crazy ants obtain much of their food requirements from scale insects, serious plant pests that feed on sap of trees and release honeydew, a sugary liquid. Ants eat honeydew, and in return protect the scale from their enemies and spread them among trees, an example of mutualism. The honeydew not eaten by the ants drips onto the trees and encourages the growth of sooty mold over the leaves and stems. This gives plants an ugly black appearance and reduces their health and vigor.

The ants protect the insects by "nannying" the mobile crawler stages and protecting them against their natural enemies.^[16] Experiments have shown that this connection is so strong that, in environments where A. gracilipes was removed, the density of scale insects dropped by 67% within 11 weeks, and to zero after 12 months.^[17]

In Australia

In Australia, yellow crazy ants have been found at more than 30 sites in Queensland, and in Arnhem Land in the Northern Territory, where a large scattered population exists.^[18] A single New South Wales infestation was detected and eradicated, and, in Western Australia, yellow crazy ants have been intercepted in shipping freight arriving at Fremantle.^[19]

Queensland's main infestation is 830 hectares (2,100 acres) in and around Wet Tropics of Queensland rainforest, a World Heritage Site.^[18] The Northern Territory infestation covers 2,500 square kilometres (970 sq mi),^[19] an area larger than the Australian Capital Territory.^[20]

Climate modelling indicates yellow crazy ants could spread across northern Australia from Queensland to Western Australia, across much of Queensland and into coastal and inland parts of New South Wales.^[19] Areas with the most ideal habitat and climatic conditions, such as the Wet Tropics of Queensland rainforests, are likely to experience the highest impacts.^[21]

A cost–benefit analysis by the Queensland government undertaken in 2012 found that yellow crazy ants could cost Australia's economy over A$3 billion if the ants were not treated. This analysis did not take potential impacts on Australia's biodiversity into account.^[21] The known impacts of crazy ants in tropical rainforests overseas may provide useful insights into these impacts, bearing in mind that the most significant impacts are associated with relatively small islands, such as Christmas Island.^[19][7]

Impact on Christmas Island

Crazy ants have had a profound impact on the biodiversity of Christmas Island.^[19][7]

The crazy ant has a significant destructive impact on the island's ecosystem, killing and displacing crabs on the forest floor. The supercolonies also devastate crab numbers migrating to the coast. This has seen a rapid depletion in the number of land crabs^[7] — killing up to 20 million of them^[7] — which are vital to Christmas Island's biodiversity; land crabs are a keystone species in the forest ecology: they dig burrows, turn over the soil, and fertilize it with their droppings.^[22]

Seedlings that were previously eaten by crabs started to grow and, as a result, changed the structure of the forest. Weeds have spread into the rainforest because there are no crabs to control them. One of the most noticeable changes in the forest is the increased numbers of the stinging tree Dendrocnide peltata, which now flourishes in many areas frequently visited by humans. The forest canopy also changed as the scale insects tended by yellow crazy ants multiplied and killed mature trees.^[23][21]

Christmas Island red crabs are completely wiped out in infested areas.^[7] Populations of other ground and canopy dwelling animals, such as reptiles and other leaf litter fauna, have also decreased. During crab migrations, many crabs move through areas infested with ants and are killed. Studies show that the ant has displaced an estimated 15–20 million^[7] crabs by occupying their burrows, killing and eating resident crabs, and using their burrows as nest sites. This factor has greatly depleted red crabs, and made their annual land migrations far more perilous.^[24][25]

Although crazy ants do not bite or sting, they spray formic acid as a defence mechanism and to subdue their prey. In areas of high ant density, the movement of a land crab disturbs the ants and, as a result, the ants instinctively spray formic acid as a form of defence. The high levels of formic acid at ground level eventually overwhelm the crabs, and they are usually blinded then eventually die from dehydration (while attempting to flush off the formic acid) and exhaustion. As the dead crabs decay, the protein becomes available to the ants.^[21]

Crazy ants kill fauna, but encourage scale insects. Increased densities of scale insects cause forest die back, and even the death of large forest trees. These changes create a cascade of negative impacts, including weed invasion, significantly altering the forest landscape.

Supercolonies

Christmas Island is a focal point for international control efforts. These supercolonies spread farther and cause more damage than single colonies, and they pose the single greatest known threat to the island's biodiversity.

Staff from Christmas Island National Park have worked in recent years to keep ant numbers in check. With help from the Christmas Island Crazy Ant Scientific Advisory Panel and support from the Australian Government they are holding ground.

Another supercolony nearly devastated the bird fauna of Johnston Atoll in the Pacific Ocean. The single massive colony was found to occupy nearly a quarter of the island, with up to 1,000 queens in a plot of land 6 metres (20 ft) wide. The infestation is thought to have been eradicated.^[26]

Control measures

To reduce the impacts of crazy ants on red crabs and Christmas Island's ecosystems the Parks Australia carried out a major aerial baiting program in 2009, to follow up the first aerial baiting conducted in 2002. The first step was conducting an extensive island-wide survey to determine the exact locations of the supercolonies. For several months, staff traversed the island surveying over 900 sites. The result was a map of crazy ant supercolonies and red crab burrow densities, together with other biodiversity data.

In September 2009, a helicopter was used to precisely bait crazy ant supercolonies, which covered 784 hectares (1,940 acres) of the island. A very low concentration of fipronil bait (0.1%) was used to control the ants. Monthly monitoring of these baited supercolony sites shows that crazy ant densities were reduced by 99%.

Park staff placed a high emphasis on minimising non-target impact of baiting. Food lures were dropped from a helicopter to attract robber crabs away from areas that were about to be baited. This technique, combined with the low concentration fipronil bait, proved to be highly successful with extremely low numbers of robber crabs and no red crabs known to be killed by the baiting.

While baiting has slowed the decline of the red crab, its effects on the crazy ant populations are only temporary, as escaping colonies invade the treated areas again, and it is expensive, requiring much man power. In an effort to find a better control, after research, Australian Parks in December 2016 imported Tachardiaephagus somervillei, a small (2 millimetres (5⁄64 in)) wasp and began breeding them for release. The wasp, which attacks only scale insects, is a voracious predator of what is believed to be one of the crazy ant's largest source of honeydew on Christmas Island, the yellow lac scale insect.^[27]

Researchers from La Trobe University in Melbourne, funded by Parks Australia, began looking for biological controls in 2009. While the ants are omnivores, studies have shown honeydew is an important part of the diet of Christmas Island crazy ants. Samples of ants taken from colonies that are growing rapidly have more honeydew in their diet than when the colonies decline. Further, restricting access to honeydew, by binding trees where the scale insects feed, dramatically reduced the colony as ant activity on the ground fell by 95% in just four weeks.^[28] In the laboratory, colonies with limited sources of sugar were compared to colonies with access to abundant sugar. Those with abundant sugar had more fertile queens and lower death rates among workers. The workers were also more aggressive toward other ant species and explored their environments more. This is believed to show why the ants decline when deprived of access to scale insects in the field, and confirm reduced honeydew will greatly reduce the ants' ability to form super colonies.^[24]

While controlling the scale insect is expected to control the yellow crazy ant on Christmas Island, on mainland Australia it is thought this would not help. There are at least a dozen honeydew producing insects as well as extrafloral nectar from native acacia trees, all of which fuel yellow crazy ants.^[27]

Experts continue to call for a fully funded, long term baiting program on mainland Australia.^[29]

References

La Flava frenezformiko (Anoplolepis gracilipes) estas specio de formiko, enmetita akcidente en norda Aŭstralio kaj en Kristnaska Insulo en la Hinda Oceano, kiu fikaŭzis teruran ekologian damaĝon en ambaŭ lokoj.

Ĝi estas populare konataj kiel "frenezaj" pro siaj sendirektaj movoj kaze de ĝenado, kaj kun siaj longaj kruroj kaj antenoj ĝi estas unu el plej grandaj invadaj formikospecioj en la mondo.^[1]

Kun la ruĝa importita fajrformiko (Solenopsis invicta), la grandkapa formiko (Pheidole megacephala), la malgranda fajrformiko (Wasmannia auropunctata), kaj la Argentina formiko (Linepithema humile), la Flava frenezformiko estas unu el la kvin specioj de formiko plej konataj pro sia invada kutimaro kaj detruegaj ekologiaj efikoj,^[2] kiel ekzemple ke ĝi mortigis ĉirkaŭ 10–15 milionoj de Kristnaskinsulaj ruĝaj kraboj en ĵusaj jaroj.^[3]. Konata ankaŭ kiel longkrura aŭ maldiva formiko, ĝi estis listita inter la plej 100 detruaj invadantoj de la mondo. Ĝi invadis ekosistemojn el Havajo al Sejŝeloj, kaj formis superformikarojn en Kristnaska Insulo en la Hinda Oceano.

Notoj

1. ↑ Pests and Diseases Image Library: Anoplolepis gracilipes.
2. ↑ Global Invasive Species Database: Anoplolepis gracilipes.
3. ↑ Dennis J. O'Dowd, Peter T. Green & P. S. Lake (2003). “Invasional 'meltdown' on an oceanic island”, Ecology Letters (PDF) 6 (9), p. 812–817. doi:10.1046/j.1461-0248.2003.00512.x.

La hormiga loca u hormiga zancona (Anoplolepis gracilipes) es una especie de hormiga de la subfamilia Formicinae, comúnmente amarilla, asociada al hombre como modificadora del ambiente, ya sean áreas agrícolas o zonas urbanas. En algunas islas tropicales incluida la isla de Navidad, ha adquirido grandes densidades, afectando a algunas poblaciones de invertebrados y vertebrados nativos, especialmente algunos pájaros. En algunos casos, ha resultado en el cambio de composición forestal y la disminución de los ciclos nutritivos, esto afecta la fauna nativa por la competencia de los recursos de comida. Al mermar la biodiversidad, indirectamente amenaza los sectores turísticos. Esta relación con varios insectos productores de miel, afecta la flora nativa y causa daños significativos a las plantas y pérdidas económicas en sistemas agrícolas.

Está incluida en la lista 100 de las especies exóticas invasoras más dañinas del mundo^[1]​ de la Unión Internacional para la Conservación de la Naturaleza.

Descripción

Es una de las hormigas invasoras de mayor tamaño ya que llegan a medir más de 5mm (las hormigas invasoras normalmente miden de uno a dos milímetros como máximo). Esta especie también es reconocida por sus largas patas y antenas, las obreras son monomórficas. Tienen un largo y esbelto cuerpo. Pueden matar o someter presas invertebradas o pequeños vertebrados rociando un ácido.

Hábitat

Se encuentran en áreas agrícolas, bosques naturales, bosques plantados, maleza-arbustos-pastos, áreas urbanas, cursos de agua, áreas costeras.

Las hormigas invasoras son conocidas por invadir hábitats como áreas urbanas, campos agrícolas, límites de los bosques.

La habilidad de la hormiga loca de vivir en áreas habitadas por los humanos, se ha convertido en una seria peste, en muchos casas y edificios, también es conocida por colonizar varios sistemas agrícolas incluidos. El cultivo de canela, de café y plantaciones de coco. En regiones agrícolas es fácil encontrar su nido en la base o en la corona del cultivo de las plantas.

Los requerimientos de los nidos de las hormigas, son generales, se pueden ubicar debajo de hojas en descomposición o en grietas o hendiduras.

Aunque la hormiga loca amarilla típicamente hace los nidos bajo las hojas en descomposición, o en agujeros en la tierra, su habilidad para buscar alimento, a lo largo del día y la noche y sobre una gran variedad de temperaturas le permite invadir rápidamente ecosistemas. Temperaturas superiores a 44º detiene el trabajo de las obreras. La actividad empieza a declinar a los 25°C y el forrajeo puede ser limitado por la lluvia.

Distribución geográfica

Esta hormiga, al ser pobremente estudiada no tiene un sitio nativo conocido con certeza. Puede haber sido originada en Asia o África.

Ha sido introducida en algunas partes de África, Asia, Australia y Sudamérica, aunque últimamente se están localizando en la zona sur de España.^[2]​ Ha sido introducida en algunas islas del Caribe, islas del océano Índico e islas del océano Pacífico. Se ha diseminado transportada por el suelo y la producción de madera, por el aire en avión. Transportada en material empaquetado y madera. Transportada en vehículos, maquinaria, botas, aviones. Transportada en contenedores. Además de introducciones deliberadas de control biológico de plantas apestadas de coco, café y plantaciones de cacao.

Reproducción

Las colonias son en forma de polígono. Se producen obreras constantemente a lo largo del año. La descendencia sexual puede ocurrir a lo largo del año, pero generalmente se produce estacionalmente.

Ciclo vital

La vida de una de estas hormigas está estimada entre 76 a 84 días. Los huevos eclosionan entre 18 a 20 días y el desarrollo de la larva de las obreras es de 16 a 20 días, mientras que el desarrollo de las reinas es de 30 a 34 días.

Métodos de dispersión local

La proporción de propagación natural es baja. Solamente por la separación, dependen en gran medida de los medios humanos.

Programa de prevención de las hormigas del Pacífico

Es una propuesta preparada por la protección, organización de las plantas del Pacífico con el fin de prevenir la red importada de la hormiga de fuego y otras especies de hormigas invasoras sobre los países del Pacífico.

Los principales tóxicos de los cebos de hormigas actúan bastante rápido lo que puede provocar que acaben muy rápido con las obreras y no alcancen a distribuir el veneno por la colonia. Estos han sido distribuidos por helicóptero en la isla de Navidad.

Tiene una amplia dieta, característica de las hormigas invasoras. Es capaz de obtener nutrientes de varios recursos incluidos granos, semillas, artrópodos, vegetación en descomposición, isópodos, miriápodos, moluscos, arácnidos y cangrejos de tierra.

Referencias

Anoplolepis gracilipes on muurahaislaji Formicinae-alaheimossa. Noin 4 mm:n mittainen Anoplolepsis gracilipes elää keskimäärin 76-84 vuorokautta. Se on yksi viidestä vaeltajamuurahaislajista. Neljä muuta ovat tulimuurahainen (Solenopsis invicta), isopäinen muurahainen (Pheidole megacephala), pieni tulimuurahainen (Wasmannia auropunctata) ja argentiinalainen muurahainen (Linepithema humile). Lajin englanninkielinen nimi "yellow crazy ant" (keltainen hullu muurahainen) viittaa sen väriin ja "hulluun" liikehdintään häirittynä. Lajin alkuperäistä elinaluetta ei varmuudella tiedetä, mutta arvellaan sen olleen Länsi-Afrikassa. Lajia esiintyy tropiikissa ja subtropiikissa, jonne se on levinnyt laivojen mukana. Sitä pidetään nykyisin yhtenä maailman sadasta haitallisimmasta vieraslajista^[1]. Erityisenä vitsauksena sitä on Australian pohjoisosissa ja Joulusaarilla, jossa se on muodostanut superkolonioita vallaten 30 % saaren sademetsistä. Joulusaarella on kokeiltu sen hävittämistä fiproniiliä sisältävillä syöteillä.

Lähteet

Tämä artikkeli tai sen osa on käännetty tai siihen on haettu tietoja muunkielisen Wikipedian artikkelista.
Alkuperäinen artikkeli: en:Yellow crazy ant

Anoplolepis gracilipes ou fourmi folle jaune^[1], est une espèce de fourmis originaire d'Afrique et d'Asie^[2] devenue invasive en Australie, à Tahiti et sur l'île Christmas.

Sa manière frénétique de se mouvoir de manière a priori désordonnée lui a valu le surnom de « fourmi folle » ^[3].

Caractéristiques

Cette espèce de fourmis est omnivore et polygyne. De plus, c'est une espèce à développement très rapide et dont les différentes fourmilières ne sont jamais agressives entre elles.

Cette fourmi ne présente pas de polymorphisme. Les ouvrières font entre 4 et 5 mm pour une espérance de vie de 3 mois. Les gynes font jusqu'à 7 mm^[3].

Notes

Voir aussi

Références externes

• Ressources relatives au vivant :
  • Australian Faunal Directory
  • Fauna Europaea
  • Nederlands Soortenregister
  • TAXREF (INPN)
  • (en) Animal Diversity Web
  • (en) Catalogue of Life in Taiwan
  • (en) EPPO Global Database
  • (en) EU-nomen
  • (en) European Nature Information System
  • (en) Global Biodiversity Information Facility
  • (en) Global Invasive Species Database
  • (en) iNaturalist
  • (en) Interim Register of Marine and Nonmarine Genera
  • (en) Invasive Species Compendium
  • (en) Système d'information taxonomique intégré
• (en) Référence Tree of Life Web Project : Anoplolepis gracilipes
• (en) Référence Fauna Europaea : Anoplolepis gracilipes
• (fr+en) Référence ITIS : Anoplolepis gracilipes (Smith, 1857)
• (en) Référence Animal Diversity Web : Anoplolepis gracilipes
• (en) Référence NCBI : Anoplolepis gracilipes (taxons inclus)
• (en) Référence GISD : espèce Anoplolepis gracilipes
• (fr) Référence INPN : Anoplolepis gracilipes (Smith, 1857) (consulté le 14 octobre 2018)

Semut Gila Kuning (Anoplolepis gracilipes) adalah spesies semut yang pada awalnya diperkenalkan sengaja ke utara Australia dan Pulau Christmas di Samudera Hindia. Semut ini telah mendatangkan kerusakan ekologis di kedua lokasi tersebut. Semut ini merupakan salah satu spesies invasif terbesar di dunia.^[1] Semut ini telah menginvasi ekosistem dari Hawaii sampai ke Seychelles, dan membentuk supercoloni di Pulau Christmas Samudera Hindia.

Sebagai spesies invasif

Semut ini sangat agresif dan menggunakan senjata asam format yang mampu mengalahkan hewan yang lebih besar. Semut ini di Pulau Chrismast mempengaruhi populasi Ketam kenari dan Cikalang christmas dengan menggangu bahkan memangsa hewan muda tersebut. Dengan tidak adanya predator sehingga membuat spesies ini semakin berkembang cepat.

Semut ini juga menyebabkan ketidakseimbangan ekosistem, terutama jika honeydew yang dikeluarkan tidak dipanen oleh semut, tapi jatuh ke bagian dasar tanaman dan mengendap di sana sebagai lengket, massa buram. Komposisi ini mencegah fotosintesis tanaman yang bersangkutan dan dengan demikian menyebabkan kerusakan kayu lebih lanjut, khususnya dari Pulau Natal. Para ilmuwan khawatir bahwa keanekaragaman hayati yang berkurang sejak semut memangsa hewan muda yang ada di Pulau Chrismas.^[2]

Terdapat predator bagi semut ini yang dilaporkan di Sulawesi yaitu jenis Kodok Sulawesi yang mampu tahan terhadap serangan asam format semut ini.

Persebaran

Habitat alami kuning gila semut tidak diketahui, tetapi telah berspekulasi bahwa spesies berasal dari Afrika Barat. Telah diperkenalkan ke berbagai lingkungan tropis dan subtropis, termasuk pulau-pulau Karibia, beberapa pulau Samudera Hindia (Seychelles, Madagaskar, Mauritius, Reunion, Kepulauan Cocos dan Kepulauan Natal) dan beberapa kepulauan Pasifik (Kaledonia Baru, Hawaii, Polinesia Prancis, Okinawa, Vanuatu, Mikronesia dan Galapagos).^[3] Spesies telah dikenal untuk menempati sistem pertanian seperti kayu manis, jeruk, kopi dan kelapa. Karena semut memiliki kebiasaan bersarang umum, mereka mampu untuk menyebar melalui truk, kapal dan bentuk lain dari transportasi manusia.

Koloni semut gila ini menyebar ketika ratu dikawinkan dan pekerja meninggalkan sarang untuk membangun yang baru, dan jarang melalui penerbangan melalui bentuk reproduksi bersayap perempuan. Umumnya, koloni yang menyebarkan melalui "pemula" memiliki tingkat lebih rendah dari penyebaran dan membutuhkan intervensi manusia untuk mencapai daerah yang jauh. Telah dicatat bahwa A. gracilipes bergerak di sekitar 37-400 meter per tahun di Seychelles . Sebuah survei di Pulau Christmas, bagaimanapun, menghasilkan kecepatan penyebaran rata-rata tiga meter per hari, setara dengan satu kilometer per tahun.^[4]

Untuk waktu yang lama tidak ada obat penawar yang efektif untuk semut ini. Dengan insektisida dosis tinggi tidak ada keberhasilan yang signifikan telah dicapai. Dalam sebuah percobaan yang dilakukan tahun 2009 dosis rendah fipronil - umpan, kepadatan koloni semut berkurang sebesar 99%. Pemerintah Australia mengeluarkan 4 juta AUD yang disediakan untuk mengeksplorasi tindakan defensif lainnya termasuk studi yang dilakukan La Trobe University dan Monash University.^[5]

Catatan Kaki

Anoplolepis gracilipes (F.Smith, 1857) è una formica della sottofamiglia Formicinae, comunemente nota come formica pazza gialla, a causa dei frenetici movimenti erratici che compie quando disturbata.^[1]

È una specie invasiva inserita nella lista delle 100 of the World's Worst Invasive Alien Species.^[2]

Descrizione

Anoplolepis gracilipes è una formica di taglia medio-piccola (lunghezza da 2 a 5 mm), caratterizzata da zampe e antenne particolarmente lunghe; ha colorazione variabile dal giallo al bruno, con il gastro più scuro del capo e del torace.^[1]

Distribuzione e habitat

La specie è ritenuta nativa dell'Africa orientale ma a seguito di ripetute introduzioni ha stabilito estese colonie in Asia tropicale, in Oceania e nei Caraibi.^[3] È stata introdotta dai trasporti umani in diversi paesi della fascia tropicale e subtropicale incluse numerose isole dell'oceano Indiano (Seychelles, Madagascar, Mauritius, Réunion, le isole Cocos e Christmas Island) e del Pacifico (Nuova Caledonia, Hawaii, Polinesia francese, Okinawa, Vanuatu, Micronesia e Galápagos).^[4][5]

Biologia

È una specie poliginica, cioè che forma colonie in cui sono presenti più regine, e polidomica, cioè con più nidi contigui; forma aggregazioni molto numerose, denominate "supercolonie", in cui gli individui si muovono liberamente tra i nidi.^[4][6]

Esse nidificano prevalentemente sotto la lettiera o in buche nel terreno, ma talora costruiscono il nido all'interno del tronco degli alberi, o sulla sommità delle palme.^[1]

Possono aggredire e talora uccidere, spruzzando grosse quantità di acido formico, sia invertebrati di taglia molto maggiore della loro, che piccoli vertebrati, sino a prede della dimensione di un uccello.^[1]

Queste formiche stabiliscono un rapporto mutualistico con afidi e cocciniglie (ordine Rincoti, sottordine Omotteri, sezione Sternorrhyncha), parassiti di diverse specie di piante. Le formiche soddisfano gran parte del loro bisogno di nutrimento dalla melata, un liquido zuccherino prodotto dagli afidi. In cambio le formiche proteggono gli afidi e le loro neanidi dai loro potenziali predatori e ne facilitano la diffusione sulle piante.^[7]

Impatto ecologico

La specie è stata introdotta accidentalmente in numerosi ambienti insulari e a causa della sua invasività ha spesso causato seri danni agli ecosistemi nativi.^[1][8].

Paradigmatico è il caso dell'Isola di Natale (in inglese Christmas Island), una piccola isola appartenente politicamente all'Australia e situata nell'Oceano Indiano a sud dell'Indonesia, nella quale le formiche gialle furono introdotte tra il 1915 e il 1934, facendo registrare una crescita esplosiva e arrivando a rappresentare in breve una seria minaccia per l'equilibrio ecologico della foresta pluviale dell'isola.^[9] Il diffondersi delle supercolonie di questa formica esotica ha infatti portato alla morte di milioni di esemplari dell'endemico granchio rosso Gecarcoidea natalis, con drammatiche ricadute sull'ecosistema forestale. In aggiunta a ciò l'espansione delle supercolonie di formiche si è associata ad un aumento delle infestazioni da cocciniglie, con effetti devastanti sulle principali specie arboree. Tali modificazioni dell'habitat hanno avuto un impatto negativo su numerose specie di uccelli, rettili e mammiferi di interesse conservazionistico come, per esempio, la sula di Abbott (Papasula abbotti), la fregata di Andrews (Fregata andrewsi), il gufastore di Christmas (Ninox natalis), il tordo dell'isola di Natale (Turdus poliocephalus erythropleurus), lo scinco dalla coda blu dell'isola di Natale (Cryptoblepharus egeriae), il geco dell'isola di Natale (Lepidodactylus listeri) e il toporagno dell'isola di Natale (Crocidura trichura).

Note

De hazewindmier^[1] (Anoplolepis gracilipes) is een mierensoort uit de onderfamilie van de schubmieren (Formicinae).^[2] De wetenschappelijke naam van de soort is voor het eerst geldig gepubliceerd in 1857 door Frederick Smith. In het Engels worden ze yellow crazy ant genoemd, gele gekke mier, waarschijnlijk vanwege hun wilde bewegingen als ze verstoord worden.^[3]

Deze mier werd per ongeluk geïntroduceerd in Noord-Australië; daar werd hij in 1978 voor het eerst aangetroffen, in het regenwoud van het Atherton Tableland, een hoogvlakte in de deelstaat Queensland. Verder komt de mier nu voor op Christmaseiland en in andere tropische en subtropische gebieden. Waar deze soort oorspronkelijk vandaan komt is onbekend; men vermoedt dat de mier afkomstig is uit West-Afrika.

Schadelijke exoot

Als exoot staat deze mier in een IUCN-lijst van de honderd ergste invasieve soorten.^[4]

Christmaseiland

De mieren zijn bekend door hun invloed op het ecosysteem van Christmaseiland, 350 kilometer ten zuiden van Java in de Indische Oceaan. Op het eiland doden ze landkrabben, bodembewonende reptielen en andere fauna die anders foerageerde op de afgevallen bladeren. De aanwezigheid van kolonies van deze roofmier heeft daardoor het karakter en de biodiversiteit van het bos totaal veranderd.^[5]

Uit onderzoek op Christmaseiland bleek dat de hazewindmier daar een destructieve invloed heeft op het ecosysteem. De mieren doden de landkrabben, vooral de rode landkrab en nemen hun ondergrondse holen in bezit. Deze krabben zijn van groot belang voor het oorspronkelijke ecosysteem van het bos, doordat ze foerageren op de bosbodem en er holen graven. Daardoor houden zij de grond luchtig en bemesten die met hun uitwerpselen. Bovendien eten de krabben zaailingen en voorkomen daardoor dat bepaalde planten, heesters en bomen groot worden. Waar de krabben verdwijnen, gaan stekelige struiken uit de brandnetelfamilie, zoals Dendrocnide peltata, overheersen.

Een dode gekko wordt door hazewindmieren weggesleept.

Anoplolepis gracilipes é uma espécie de formiga do gênero Anoplolepis, pertencente à subfamília Formicinae. Foram introduzidas acidentalmente na Austrália, sendo consideradas uma praga. Elas são coloquialmente chamadas de "loucas" por causa de seus movimentos erráticos quando perturbadas, e são uma das maiores espécies de formigas invasoras.^[1]

Referências

Formica longipes Jerdon
Formica trifasciata Smith
Anoplolepis longipes (Jerdon)
Plagiolepis longipes (Jerdon)
Prenolepis gracilipes (Smith)
Plagiolepis gracilipes (Smith)

Anoplolepis gracilipes je vrsta mravlje, razširjena po tropskih in subtropskih predelih sveta.

Opis

Je razmeroma velika mravlja; delavke merijo 5 mm v dolžino, imajo vitko telo z izrazito dolgimi nogami ter tipalnicami. Sestavljene oči so razmeroma velike in izbuljene. Zunanji skelet je mehak, rumeno-rjave barve, le zadek je nekoliko temnejši. Vse delavke so morfološko enake. V angleško govorečih območjih je vrsta zaradi podivjanega opletanja delavk, kadar se počutijo ogrožene, dobila ljudsko ime »yellow crazy ant« (nora rumena mravlja).

Kolonije so lahko poligine, kar pomeni, da imajo več kraljic. Te rojevajo delavke skozi vse leto, vendar so opazna sezonska nihanja z viškom pred deževno dobo. Občasno se pojavljajo krilati osebki, ki se razmnožujejo spolno, vendar nove kolonije nastanejo v večini primerov z odcepitvijo. Ocenjujejo, da traja življenjski cikel 76 do 84 dni od tega razvoj okrog dva meseca (dva meseca in pol pri kraljicah). Delavke iz poliginih kolonij srdito branijo svoje kraljice in včasih uprizarjajo plenilske pohode na sosednje kolonije. Pri kolonijah s samo eno kraljico pa lahko pride do pojava t. i. »superkolonije«, razpršenih kolonij s prosto izmenjavo delavk. Taka superkolonija se lahko razprostira na površini do 150 ha in doseže gostoto 20 milijonov delavk na hektar. Posamična kolonija največkrat šteje okrog 4000 delavk.

Ekologija in razširjenost

Delavke vlečejo mrtvega gekona proti mravljišču

Vrsta je vsejedi generalist. Delavke po teritoriju pobirajo mrhovino in plenijo različne nevretenčarje, kot so enakonožci, stonoge, mehkužci, pajkovci in žuželke, pa tudi manjše ptiče, plazilce in sesalce. Plen onesposobijo tako, da ga škropijo z mravljinčno kislino, ki jo uporabljajo tudi za obrambo. Za optimalen razvoj potrebujejo hrano, bogato z beljakovinami, pomemben delež prehrane pa predstavljajo ogljikovi hidrati. Vir le-teh je lahko nektar, pogosto pa delavke tudi nabirajo mano kaparjev, ki jih aktivno čuvajo. Zares množične kolonije so odvisne od kaparjev. Hrano iščejo podnevi in ponoči, pri širokem razponu temperatur in po vseh možnih površinah znotraj teritorija, celo v krošnjah deževnih gozdov.

Gnezdijo lahko v raznolikih habitatih; primarno je to vrsta nižinskih tropskih deževnih gozdov, pojavljajo pa se tudi v obalnih predelih, traviščih, močvirnatih gozdovih in v grmičevju. Vrsta je znana po tem, da uspešno poseli območja, ki jih je spremenil človek, tako da najdemo kolonije na kmetijskih območjih, v plantažah dreves in urbanih območjih, pri tem pa zahajajo tudi v notranjost stavb. Gnezdo je po navadi med rastlinskim opadom ali v luknjah v tleh.

Izvorno območje razširjenosti vrste ni natančno znano. Domnevajo, da je to bodisi Afrika, kjer živijo preostali predstavniki tega rodu, bodisi Južna Azija.

Kot invazivna vrsta

V zadnjem stoletju mravlja Anoplolepis gracilipes intenzivno poseljuje nova območja in zaradi agresivnosti izriva avtohtono favno, zato velja za eno najhujših invazivnih vrst. Vnešena je bila in uspeva v delih Afrike, Južne Amerike in Avstralije, poleg tega pa še na Karibe in otoke v Indijskem ter Tihem oceanu. Opazili so jih tudi na zahodnih obalah Mehike in ZDA. Posebej resno grožnjo za avtohtono favno predstavlja na Božičnem otoku v Indijskem oceanu, kjer je populacija iz še ne pojasnjenih razlogov nenadoma eksplodirala in poselila tudi neokrnjene monsunske gozdove. Zaradi množičnosti iztreblja populacije več endemičnih vrst, kot so kopenska rakovica vrste Gecarcoidea natalis. Poleg tega povzroča škodo tudi posredno - ker delavke skrbijo za kaparje, so se močno razmnožili tudi ti. Mana, ki kaplja z njih, spodbuja rast plesni, te pa uničujejo drevje.

Na daljše razdalje je najpomembnejši prenašalec človek, ki vnaša mravlje v nova okolja s prevozom okuženih kmetijskih pridelkov, okrasnih rastlin, lesa, prsti in kmetijske mehanizacije.

Viri

• Harris, Richard; Abbott, Kirsty; Berry, Jo. "Anoplolepis gracilipes (Smith)" (PDF). Invasive Ant Threat - Information Sheet No. 1. Landcare Research. Pridobljeno dne 29.11.2012.
• O'Dowd, Dennis (2009). "Anoplolepis gracilipes (insect)". Global Invasive Species Database. Pridobljeno dne 29.11.2012.

Kiến vàng điên, tên khoa học Anoplolepis gracilipes, là một loài trong chi Anoplolepis, họ kiến. Loài này được F. Smith phân loại vào năm 1857.

Chúng được gọi là kiến vàng "điên" bởi chúng di chuyển hỗn loạn và là một trong những động vật xâm hại nguy hiểm nhất trên thế giới. Khả năng phát triển nhanh của chúng hình thành các siêu lãnh thổ đông đúc với tỷ lệ lên đến 1.000 con/km2.

Các nhà khoa học cho rằng kiến vàng điên bắt nguồn từ châu Phi rồi chu du tới châu Á thông qua các vật liệu bao gói hoặc thùng hàng.^[1] Chúng xâm nhập một cách tình cờ vào lãnh thổ Úc và Đảo Giáng Sinh trên Ấn Độ Dương và lần đầu tiên được phát hiện tại miền Bắc Australia vào năm 1990. Số lượng tăng nhanh chỉ trong vài năm, kiến vàng điên ăn hệ thực vật địa phương, tiêu diệt hoặc lấn át các loài động vật không xương sống bản địa, làm hủy hoại hệ sinh thái ở những nơi mà chúng đi qua.

Phân bố và đặc tính thông thường

Nơi phân bố nguyên thủy của loài kiến điên này vẫn chưa biết, nhưng có giả thuyết cho rằng chúng bắt nguồn từ Tây Phi. Sau đó, chúng được đưa tới những vùng xích đạo hoặc bán xích đạo qua đường thủy (trên các thùng hàng...) như vùng biển Caribbe, các quần đảo Ấn Độ Dương, và Thái Bình Dương.^[2][3] Kiến vàng điên đã xâm nhập hệ thống nông nghiệp như các loài cây quế, cam, cà phê và dừa.

Loài kiến vàng điên được gọi là "những kẻ ăn rác" và có chế độ ăn lớn, một chế độ rất phổ biến với những loài xâm lấn. Kiến điên ăn đủ thứ, từ ngũ cốc, ngô, hạt cây... tới cua, các loài côn trùng... Như các loài kiến khác, kiến vàng điên cần một chế độ ăn giàu đạm (protein) để kiến chúa đẻ trứng, và chế độ ăn giàu cacbohydrat để kiến thợ làm việc.

Trên đảo Giáng sinh

Khi xâm lấn trên đảo Giáng sinh, kiến vàng điên đã thay đổi mạnh mẽ hệ sinh thái của đảo này. Chúng ăn tất cả mọi thứ, từ bướm, côn trùng, thạch thùng... Sự thay đổi lớn nhất mà loài kiến này gây ra chính là làm loài cua đỏ bị giảm sút. Trước kia, số các thể cua đỏ trên đảo Christmas là khoảng 43,7 triệu con trưởng thành.^[4] Từ khi kiến vàng điên xâm nhập đảo Christmas, số lượng cua bị tiêu diệt là 10-15 triệu con.^[5]

Các mối nguy hại

Trong các thập kỷ gần đây loài kiến vàng điên được xếp vào danh sách 100 loài xâm lăng nguy hiểm nhất. Các cư dân ở Hawaii và Madagascar đã cố tiêu diệt loài kiến này song chưa có giải pháp. Đảo Giáng sinh là tâm điểm cho những biện pháp nghiên cứu tiêu diệt kiến vàng điên.

Hình ảnh

• Hình ảnh một con kiến vàng điên phóng to.

• Phần đầu của con kiến vàng điên phóng to.

• Một con thạch sùng bị đàn kiến vàng điên ăn thịt.

Chú thích

Tham khảo

• Dữ liệu liên quan tới Anoplolepis gracilipes tại Wikispecies
• Phương tiện liên quan tới Anoplolepis gracilipes tại Wikimedia Commons

• 1 Физиология
  • 1.1 Суперколонии
• 2 Географический охват и распространение
• 3 Питание
  • 3.1 Мутуализм
• 4 Вторжение на остров Рождества
• 5 Другие угрозы
• 6 Меры
• 7 Примечания
• 8 Литература

長足捷蟻（學名：Anoplolepis gracilipes），英文俗名：yellow crazy ant（黃瘋蟻）、long-legged ant（長腿蟻）或 Maldive ant（馬爾代夫蟻），中文译名有細足捷蟻、長足捷蟻、長腳捷蟻、長角捷蟻，是捷蟻屬下的一種螞蟻，因為偶然引入澳大利亞和聖誕島，而對二地的生態系統造成了災難性影響。牠不僅是世界百大外來入侵種之一，^[2] 也是世界上體型最大的入侵螞蟻之一，長約1～2毫米（0.039～0.079英寸）。^[1][3][4]

長足捷蟻體型較大，腿部和觸角都很長，通體呈黃色或橘黃色。它廣泛分佈與世界各地的熱帶地區，在太平洋地區更為常見。^[5]

分佈

長足捷蟻的原產地據推測可能是西非，已經被引入世界各地的亞熱帶和熱帶地區。其中包括加勒比群島、印度洋的塞舌耳、馬達加斯加、毛里求斯、留尼汪、可可斯群島以及聖誕島、太平洋的新喀里多尼亞、夏威夷、法屬波利尼西亞、臺灣、沖繩、瓦努阿圖、密克羅尼西亞和加拉帕戈斯群島。^[6][7] 該物種可以寄生在肉桂、柑橘、可可和椰子樹等許多植物上，因為其巢穴就在樹幹中，因此極容易被運送木材的船隻攜帶、進而傳播到別的地區。^[1]

蟻后和工蟻可能會離開巢穴建立新居，但是其本身的擴張速度並不很快。之所以變成入侵物種大多還是人類攜帶的緣故。據報告，塞舌耳的長足捷蟻每年移動距離為400米（1,300英尺）。^[6] 不過聖誕島上的長足捷蟻的速度就快得多，達到了每日3米，每年移動約一千米。^[8]

習性

印度的一群長足捷蟻正在拖拽一條死去的壁虎

長足捷蟻的食性很廣，包括作物、昆蟲和腐屍。曾報導發現長足捷蟻主動進攻等足目、多足類、蛛形綱、蚯蚓、地蟹等生物。^[8]

像其他螞蟻一樣，長足捷蟻會利用蚜蟲、蚧殼蟲和其他胸喙类昆蟲獲取蜜露。長足捷蟻對蚜蟲的依賴性十分之大，若沒有足夠的蚜蟲提供蜜露，其擴張速度就会降低。^[6] 而相對的，長足捷蟻會為這些昆蟲提供保護。^[9] 研究顯示，如果長足捷蟻從一個地區搬走，當地的蚧殼蟲數量在11週內會下降將近7成，10個月後將完全消失。^[10]

參考文獻

노랑미친개미에 의해 끌려가는 죽은 도마뱀, 인도

노랑미친개미(영어: yellow crazy ant) 또는 긴다리비틀개미는 개미의 한 종으로, 인간의 실수로 북부 오스트레일리아와 크리스마스섬에 진출하였고, 현재는 이 두 곳에서 해충으로 간주되고 있다. 브리즈번 교외 북부지역에서도 발견된다. 이름이 '미친'개미인 이유는 이들이 생태계를 무차별로 파괴하는 주범으로서, 100대 위험한 침입종에 속하기 때문이다.^[1]

노랑미친개미는 붉은불개미, 전기개미, 아르헨티나개미 등과 함께 주요한 침입종으로 분류된다.^[2] 노랑미친개미는 100대 위험한 침입종에 속한 적이 있을 정도로 생태계에 대한 파괴력이 크다. 노랑미친개미들은 침입지에서 초군락을 형성하여 더욱 파괴적이다.

특징

신체적 특징

일개미들은 크기가 모두 같으며 약 76~84일을 산다. 몸길이가 약 4mm이며, 색은 노랑과 갈색이 섞인 색이며 배는 더 짙다. 또한 더듬이와 다리가 매우 길다. 타원형 머리에 큰턱에 이가 8개, 더듬이의 마디는 11개이다. 가슴이 가늘며 배자루마디가 굵다. 침은 없으나 개미산을 쏘아 방어하여 척추동물 같은 경우에는 즉사하지 않으나 실명하여 결국 굶어죽게 된다.

초군락

노랑미친개미들은 크리스마스섬에서 마치 하나의 군락에 속한것처럼 행동하고 높은 밀도의 초군락을 형성한다. 물론 많은 개미 종들이 초군락을 형성하기는 하나, 침입종의 경우에는 조금 다르다. 다시말해, 초군락의 형성은 각 군락의 협조와 동종간의 공격성의 부족에서 유발된다. 이런 특성은 보통 개미 군락보다 훨씬 높은 밀도를 유지 할 수 있게 한다. 제곱 미터당 2254개체라는 밀도와 제곱미터당 10.5개의 군락이라는 매우 높은 밀도가 기록된 적도 있는데, 이는 여태까지의 기록 중 가장 높다.

각주