What you need to know about the threat of invasive ants

0
304

Australia is a hotspot for ants

More ant species call Australia home than anywhere else in the world.

So a lot of eyebrows were raised when $28.8 million was allocated in Australia’s 2019-20 budget to fight just three specific ant species.

But these bad guys have the potential to change Australia’s outdoor lifestyle if not controlled, and all experts agree that not acting could cost more. In Queensland alone, the state government predicts costs of about $43 billion over 30 years if just one of those ants is left unchecked.

We spoke to some experts to find out why — and what all of us, even city-dwelling non-experts, can do to help.

Why ants are important

Ants may be small and annoying when they come into your house or attack your picnic, but they are hugely important to the larger environment. Ants are the Earth’s dominant animal group in terms of biomass, so in sheer numbers alone they matter.

“Ants are really good bioindicators,” says CSIRO health and biosecurity principle research scientist Ben Hoffmann.

That is, they play such a crucial role that land managers can check the health of the whole local environment by monitoring ants. If invasive ants move in and take over, the whole system suffers.

Mr Hoffmann says ants play a really important role for farmers and gardeners by digging tunnels that make it easier for water to soak into soil, cleaning up nature’s waste, and moving nutrients. And lots of Australian plants have evolved to rely on ants to bury their seed for them.

Seeds often have a nutritious outer section called an elaiosome, so the ants carry the seed back to the nest, eat the elaiosome, then leave the still-intact seed to grow — in what’s now well-fertilised, well-drained soil.

This happens all around the world, mostly in desert areas. But in Australia our ants have taken it to the next level, adapting this seed-collecting to almost every corner of the country.

Ants often protect mature trees by eating pests such as caterpillars, but they can also work against trees by protecting sap-sucking insects that then build up in huge numbers and overwhelm the plant. The ants farm the bugs, harvesting the sweet secretions they produce.

Invasive ants tend to do this a lot and the presence of trees — and bugs that ants can harvest — plays a major role in fuelling the march of invasive ants across new territories. Red fire ants, which are invading Brisbane, spread at a rate of 48 kilometers a year in Texas between 1957 and 1977, and up to 80 kilometers per year in China.

Of the 30 introduced species in Australia, the budget money targets the red fire ant, the crazy yellow ant, and the Argentine ant (but only in Norfolk Island). Argentine ants are found across Australia but they are too well established to fight any more. Now the battle is on to stop the others — and getting people ant-aware will be the key to winning.

“Public vigilance is one of best aids to a program like this,” Mr Hoffmann says.

“The more people who are engaged and looking, the more we find, and the more quickly they can be controlled.”

What turns a good ant bad?

Ant expert Mr Hoffmann says the official number of 1,621 ant types in Australia could be a fraction of the actual number.

“There’s possibly up to 30,000 native ant species in Australia. We don’t know.”

What we do know is that when visiting ants occasionally rock up — usually via cargo on boats — they find Australia very accommodating. They settle in so well they kill off the native ants and can kill bees, birds, reptiles, native mammals, pets — even humans who are badly stung or allergic. Ant invasions in the house can really bug the best of us, so here are some natural ways to keep them at bay.

‘Invasives’ also pose an economic threat, attacking crops and livestock and affecting exports — because no-one wants to risk bringing killer ants into their country.

The threat to our outdoor lifestyle is also huge.

That’s where Mr Hoffmann comes in. As part of his work with CSIRO health and Biosecurity in Darwin, Mr Hoffmann oversees and advises on the major ant eradication programs in Australia. He led the program that eradicated the African big-headed ant from Lord Howe Island, and has been working to control the yellow crazy ant (yes, its real name) from the Gove Peninsula in East Arnhem Land, NT.

Mr Hoffmann says many invasive species are particularly adept at quickly building large populations and overwhelming other species.

“Some form multi-queen colonies with no specific boundaries and cooperate with each other, so you end up with a supercolony. Ironically, these are often easier to control because they are self-containing, so it’s easy to draw a line around the boundary and treat the whole area.

“Fire ants have queens that can fly 5 kilometres to a new location, so it’s harder to draw a line around the colony.”

How do we stop the spread of invasive ants?

Humans are often responsible for introducing ants to new areas, so getting people to check potted plants, cuttings, fruit, garden furniture, beehives, and baled hay or straw before moving them is a key to stopping the spread.

Many areas have already introduced industry regulations controlling the movement of compost, soil, turf, mulch, manure, and quarrying/mining material. Time running out to wipe out red fire ants There is “only a small window of opportunity left” to wipe out the red fire ant, according to a report obtained by the ABC.

While Queensland is Ant Central now, huge numbers of holiday-makers visit the infested areas — from Port Douglas and Brisbane to Darwin and Arnhem Land — so we all need to be ant-smart to avoid giving a free ride to unwanted insect guests.

Biosecurity Queensland’s science manager Ross Wylie says, “The public report approximately 70 percent of all finds that we get of fire ants.”

 

Australia is a hotspot for ants

The challenge is to keep public support going until the ant is fully eradicated; even a tiny colony can quickly re-populate an area.

However, always take green waste and other rubbish to a local tip — don’t dump it in the bush — and check pot plants and garden material before moving or buying.

Queenslanders can report sightings and ask for a backyard check by calling (07) 4241 0525 (Cairns region) or by registering online. Residents of WA can use a local pest guide to identify pests.

Of the 30 introduced species in Australia, the budget money targets the red fire ant, the crazy yellow ant, and the Argentine ant (but only in Norfolk Island). Argentine ants are found across Australia but they are too well established to fight any more. Now the battle is on to stop the others — and getting people ant-aware will be the key to winning.

“Public vigilance is one of best aids to a program like this,” Mr Hoffmann says.

“The more people who are engaged and looking, the more we find, and the more quickly they can be controlled.”

What turns a good ant bad?

Ant expert Mr Hoffmann says the official number of 1,621 ant types in Australia could be a fraction of the actual number.

“There’s possibly up to 30,000 native ant species in Australia. We don’t know.”

What we do know is that when visiting ants occasionally rock up — usually via cargo on boats — they find Australia very accommodating. They settle in so well they kill off the native ants and can kill bees, birds, reptiles, native mammals, pets — even humans who are badly stung or allergic. Ant invasions in the house can really bug the best of us, so here are some natural ways to keep them at bay.

‘Invasives’ also pose an economic threat, attacking crops and livestock and affecting exports — because no-one wants to risk bringing killer ants into their country.

The threat to our outdoor lifestyle is also huge.

That’s where Mr Hoffmann comes in. As part of his work with CSIRO health and Biosecurity in Darwin, Mr Hoffmann oversees and advises on the major ant eradication programs in Australia. He led the program that eradicated the African big-headed ant from Lord Howe Island, and has been working to control the yellow crazy ant (yes, its real name) from the Gove Peninsula in East Arnhem Land, NT.

Mr Hoffmann says many invasive species are particularly adept at quickly building large populations and overwhelming other species.

“Some form multi-queen colonies with no specific boundaries and cooperate with each other, so you end up with a supercolony. Ironically, these are often easier to control because they are self-containing, so it’s easy to draw a line around the boundary and treat the whole area.

“Fire ants have queens that can fly 5 kilometres to a new location, so it’s harder to draw a line around the colony.”

How do we stop the spread of invasive ants?

Humans are often responsible for introducing ants to new areas, so getting people to check potted plants, cuttings, fruit, garden furniture, beehives, and baled hay or straw before moving them is a key to stopping the spread.

Many areas have already introduced industry regulations controlling the movement of compost, soil, turf, mulch, manure and quarrying/mining material.

While Queensland is Ant Central now, huge numbers of holiday-makers visit the infested areas — from Port Douglas and Brisbane, to Darwin and Arnhem Land — so we all need to be ant-smart to avoid giving a free ride to unwanted insect guests.

Biosecurity Queensland’s science manager Ross Wylie says, “The public report approximately 70 percent of all finds that we get of fire ants.”

The challenge is to keep public support going until the ant is fully eradicated; even a tiny colony can quickly re-populate an area.

However, always take green waste and other rubbish to a local tip — don’t dump it in the bush — and check pot plants and garden material before moving or buying.

Source:

http://skynewswire.com/australia-is-a-hotspot-for-ants

https://www.abc.net.au/life/the-threat-of-invasive-ants/11341332

 308 total views,  1 views today

LEAVE A REPLY

Please enter your comment!
Please enter your name here