| Yellow crazy ants fit the stereotype of a rapacious marauding invader. The yellow crazy ant (Anoplolepis gracilipes) is a species of ant, introduced accidentally to northern Australia and Christmas Island in the Indian Ocean, which has wreaked ecological damage in both locations. It is colloquially called “crazy” because of its erratic movements when disturbed, with its long legs and antennae making it one of the largest invasive ant species in the world. This is a “tramp ant”, a species that easily becomes established and dominant in a 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. It is on a list of “One Hundred of the World’s Worst Invasive Alien Species” formulated by the International Union for Conservation of Nature (IUCN). It has invaded ecosystems from Hawaii to Seychelles, and formed supercolonies on Christmas Island in the Indian Ocean. |
The yellow crazy ants are widespread across the tropics, and populations are especially dense in the Pacific region. The yellow crazy ant’s natural habitat is not known, but it has been speculated that the species originated in West Africa. It has been introduced into a wide range of tropical and subtropical environments including Caribbean islands, some Indian Ocean islands and some Pacific islands. The species has been known to occupy agricultural systems such as cinnamon, citrus, coffee and coconut plantations. Because the ant has generalized nesting habits, they are able to disperse via trucks, boats and other forms of human transport.
Yellow crazy ants demonstrate the power of numbers and the benefits of social cooperation. They are able to dominate large areas by forming super-colonies with multiple nests and multiple queens. The largest have up to 300 queens and extend over several hundred hectares. They spread by budding. A mated queen leaves her birth nest with some workers and sets up a new nest nearby. The boundary of a super-colony can advance approximately by 3 meter a day.
Also what is interesting here is that crazy ants have the ability to form multi-queened “super colonies”, where rather than fight each other, the offspring of different queens cooperate to form infestations. There can be several thousand ants per square metre of forest floor in these super colonies, but at any one time there are just as many ants foraging in the treetops.
A survey on Christmas Island one of the worst affected regions yielded an average spreading speed of three meters a day, the equivalent of one kilometer a year.
The species is most infamous for causing the ecological “meltdown” of Christmas Island. On Christmas Island, yellow crazy ants have reached densities of more than 2,000 ants per square metre—the highest density of foraging ants ever recorded. The ants have had a dramatic impact on the ecosystem and are linked to population declines in some species of crab, bird and plant. Yellow crazy ant impacts are varied, depending on their density and on the invaded ecosystem.
They like to think of themselves as literally being the “queens of their castles”. Crazy ants are highly aggressive to other ants. Only two of 40 ants on Christmas Island are able to coexist with yellow crazy ants. In Hawaii, yellow crazy ants aggressively defend flowers from other nectar-eaters. Their large-scale removal of insects deprives other insect-eaters, such as lizards and birds, of food. Monopolization was noted at a site near Cairns.
They cause a huge amount of damage to the biodiversity as well as to the agriculture in the areas they attack. Yellow crazy ant’s farm sap-sucking bugs for their honeydew and protect them from predators. The build-up in bugs and sugar encourages the growth of sooty mould, which can severely compromise tree health and is sometimes fatal.
Yellow crazy ants also cause agricultural damage. They have killed young chickens and pigs. They reduce yields of coffee, coconut and sugarcane crops by nesting at the base of these plants and exposing the roots to disease, and promote sooty mould disease in fruit trees. On one of the Seychelles islands, the abundance of a sap-sucking insect associated with sooty mould on citrus and cinnamon increased up to 100-fold in the presence of yellow crazy ants, and up to 90 percent of leaves were infected.
They are also known to spray formic acid which may cause burning and irritate the skin and eyes of animals and potentially humans.
Let us look at the following news article:
Federal Government gives $2m to fight yellow crazy ants south of Cairns
- Liam Parsons
- The Cairns Post
- November 11, 2013 6:14AM
RURAL MENACE: The Yellow Crazy ant, or Anoplolepsis Gracilipes.
THE war against one of the world’s most invasive pests has been given a boost after the Federal Government announced $2 million to fight yellow crazy ants south of Cairns.
The pests are about the size of green ants and spray a substance that irritates the skin and can cause temporary blindness to humans and animals.
Known for their frantic movements when disturbed, yellow crazy ants are entrenched at properties around Edmonton, south of Cairns.
But there are fears the infestation could spread to the neighboring Wet Tropics rainforests, causing severe damage to the World Heritage-listed region and local wildlife.
Wet Tropics Management Authority executive director Andrew Maclean said the ants would disturb fragile ecosystems while threatening young birds and even cassowaries.
“They’re quite aggressive,” he said.
“We would also be worried about the effect they would have on the invertebrate population, which plays an important part in the ecology.”
Mr. Maclean said recent surveys indicated the ants were confined to Edmonton, allowing the authorities to stamp them out before they spread.
“Once they’re established in a forest, the prospect of getting rid of them is pretty slim,” he said.
“It’s important you jump on these populations. We think it’s not too late to completely eradicate them.”
The money will go towards a five-year eradication program involving baits, research funding and public education and awareness programs.
Kennedy MP Bob Katter welcomed the funding and called for residents to identify and report the ants.
The funding, under the Federal Government’s Caring for Our Country grants program, comes 12 months after the State Government and Biosecurity Queensland stopped its eradication program.
Thus we can see that these pests are causing us a lot of grief and control measures are extremely costly.
In 2007, the CSIRO (Commonwealth Scientific and Industrial Research Organization) claimed it had undertaken the world’s most successful eradication of the exotic invertebrate species, Yellow Crazy Ant, in the Northern Territory of Australia. However, the need for control programs for these ants is a pressing one. We at C-Tech Corporation can provide a solution to this grave problem.
However, the need for control programs for these ants is a pressing one. We at C Tech Corporation can provide a solution to this grave problem. Termirepel™ a product by C Tech Corporation is an effective non-toxic, non-hazardous insect aversive. It works by the mechanism of repellence by which it aims at repelling the target species away from the end application. Termirepel™ can be incorporated in agricultural films during processing which can then be used to protect crops against the onslaught of these vicious ants. Termirepel™ can also be sprayed on the plants to protect them from these crazy ants.