Invasive ants: federal budget takes aim but will it be a lethal shot?



File 20190404 131415 1ag8r2w.jpg?ixlib=rb 1.1
Argentine ants are a fact of life in many parts of Australia, but can still potentially be banished from Norfolk Island.
Davefoc/Wikimedia Commons, CC BY-SA

Lori Lach, James Cook University

Amid all the usual items we expect to see in the federal budget was one that raised eyebrows: A$28.8 million for three ant eradication programs.

Yet amid the inevitable media puns about the government “upping the ant-e”, we should note that these funds are for the continuation of existing programs that have already attracted significant funding and made substantial progress. Stopping now would have meant previous funding was wasted.

The funds will go a long way towards protecting Australia’s economy and environment from the damage wrought by invasive ants. But despite the apparent cash splurge, it nevertheless falls short of what is really needed.

Of the $28.8 million, $18.3 million was for the National Red Imported Fire Ant Eradication Program. These funds are part of a $411 million, ten-year program begun in 2017 to eradicate red imported fire ants from southeast Queensland, the only place they are found in Australia.




Read more:
Cannibalism helps fire ants invade new territory


Removing these pests will avoid an estimated $1.65 billion in total costs to 19 different parts of the economy. With previous funding, the program eradicated these ants from 8,300 hectares near the Port of Brisbane, making it the world’s largest ant eradication to date.

The Yellow Crazy Ant Eradication Program was allocated $9.2 million over three years. Yellow crazy ants have caused a cascade of ecological effects on Christmas Island, and at their peak abundance temporarily blinded a Queensland cane farmer with their acid spray.

The Wet Tropics Management Authority, which runs the program, had requested $6 million per year for six years to continue removing the ant from in and around the Wet Tropics World Heritage Area. The federal funding is $3 million short of this, and the authority is still waiting to hear whether the Queensland government will provide the remainder.

Since 2013, the program has received $9.5 million from the federal government (and $3 million from the Queensland government). No yellow crazy ants have been observed in about half of the target area in more than a year. A yet-to-be published analysis estimates the benefit-cost ratio for the program as 178:1.

“It’s a mop-up operation… we’ve got our foot on the throat of this thing.”

A further $1.3 million was allocated to the Argentine Ant Eradication Strategy on Norfolk Island in the South Pacific. Argentine ants have invaded places with Mediterranean-type climates all over the world, including southwestern Western Australia and parts of southern Australia, and become firmly established. But unlike those areas, the population on Norfolk Island is still considered small enough to be eradicable, and federally funded efforts to remove them began in 2010.

Yellow crazy ants in Queensland and Argentine ants on Norfolk Island directly threaten World Heritage Areas. The ants can have significant impacts on native birds, mammals, insects, reptiles, amphibians, and plants. Getting rid of them is important for meeting Australia’s international obligations to protect World Heritage sites.

What is ant eradication?

Ant eradication means removing all individuals of a particular ant species from a given area.

The first step is to define the extent of that area. Depending on the species, this may involve visual searches and/or placing lures such as sausages, cat food, or jam to attract the ants. The public can help by notifying relevant authorities of unusual ants in their gardens, and by not transporting materials that have ants on them.

The second step is treatment. Currently, the only way to eradicate ants is with insecticidal baits. Ants’ social structure makes this particularly challenging: killing the queens is vital for eradication, but queens typically stay sheltered in the nest – the only ants we see out foraging are workers.

Some of the most problematic ant species can have hundreds of queens and tens of thousands of workers per nest. They can reach extraordinarily high densities, partly because invasive ant species, unlike most of our native ant species, do not fight one another for territories.

Yellow crazy ants, proving it is possible to feel sorry for a cockroach.
Bradley Rentz/Wikimedia Commons, CC BY-SA

Beating ants means turning their biology against them. Bait needs to be attractive enough for workers to bring back to the colony and share, but not so deadly that they die before they get there. (And yes, this means if you’re spraying foraging ants in your kitchen you won’t get rid them for good, because the queens are somewhere hidden, laying more eggs and making more ants.)

Most ant eradication programs take three to four years to fine-tune their baiting regime because of a multitude of factors that need to be considered, such as seasonal changes in ant foraging behaviour and food preference, and the desire to avoid harming non-target species. Typically, two to six treatments are required, depending on the ant species, the size of the area, and the habitat type.

Beating the 1%

The hardest part of ant eradication is the end-game. Getting rid of the final 1% requires first finding them. This may mean painstaking searches through hundreds of hectares of bushland and residential areas, and the placement of hundreds of thousands of lures. Detector dogs can be very helpful, but they cannot be used in all environments and also need substantial resources for training, handling, and maintenance.

Ironically, it is at this stage that public and political support for eradication programs is most likely to wane, because ant numbers are too low to be seen as a threat to the public, economy or environment. Yet it is vital not to stop now, or else the remaining 1% will simply build up their numbers again. Experienced staff are also lost when programs suffer cuts or delays in their funding.




Read more:
Eradicating fire ants is still possible, but we have to choose now


Disappointingly not mentioned in the budget was funding for eradicating electric ants. Like red imported fire ants, electric ants have a painful sting, and when left to multiply will eventually turn gardens and swimming pools into no-go zones. They also pose a significant threat to native animals such as the southern cassowary, and can blind animals as large as elephants.

They are currently only found in the Cairns region. The National Electric Ant Eradication Program, funded by federal and state governments, ran from 2006 until 2017 and had likely reduced numbers down to that last 1%. The program has been running on state funding with reduced staff since then, but several new detections in the past three months demonstrate the cost of the gap in funding.

In those inevitable “federal budget winners and losers” lists, invasive ants have found themselves firmly in the losers column for 2019. But it’s worth remembering that most of the world’s roughly 15,000 known ant species provide vital services for the functioning of our ecosystems.

They aerate soil and redistribute its nutrients, protect plants from herbivores, disperse seeds, and repurpose dead organisms. They may even help slow down the spread of those pesky invasive ants that are much less friendly.The Conversation

Lori Lach, Associate Professor, James Cook University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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2018-19 was Australia’s hottest summer on record, with a warm autumn likely too


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Dirty water from Queensland’s historic flooding, triggered by weeks of exceptional monsoon rains earlier in the year.
NASA Worldview/EPA

David Jones, Australian Bureau of Meteorology; Lynette Bettio, Australian Bureau of Meteorology, and Skie Tobin, Australian Bureau of Meteorology

Australian summers are getting hotter. Today marks the end of our warmest summer on record, setting new national temperature records. Worsening drought, locally significant flooding, damaging bushfires, and heatwaves capped a summer of extremes.

As we look to autumn, warmer temperatures overall and below average rainfall – especially in eastern parts of the country – are likely.

Australian summer mean temperature anomalies against the 1961–1990 average.
Bureau of Meteorology



Read more:
The stubborn high-pressure system behind Australia’s record heatwaves


Very hot…

The starkest feature of this summer was the record warmth. The national average temperature is expected to be about 2.1℃ above average, and will easily beat the previous record high set in summer 2012-13 (which was 1.28℃ warmer than average).

Very low rainfall accompanied the record heat of summer. At the national scale, each month was notably dry, and total summer rainfall was around 30% below average; the lowest for summer since 1982–83. The monsoon onset was delayed in Darwin until the 23rd of January (the latest since 1972–73) and typical monsoonal weather was absent for most of summer.

Preliminary summer 2018–19 mean temperature deciles.
Bureau of Meteorology

In December 2018 Australia saw its highest mean, maximum and minimum temperatures on record (monthly averages, compared to all other Decembers). Notable heatwaves affected the north of Australia at the start of the month, spreading to the west and south during the second half of December. Temperatures peaked at 49.3℃ at Marble Bar in Western Australia on the 27th, with mid-to-high 40s extending over larger areas.

The heat continued into January, which set a national monthly mean temperature record at 2.91℃ above the 1961–1990 average. Heatwave conditions which had emerged in December persisted, with a prolonged warm spell and numerous records set. Eight of the ten hottest days for the nation occurred during the month, while a minimum temperature of 36.6℃ at Wanaaring (Borrona Downs) in western New South Wales on the 26th set a new national minimum temperature record.

Temperatures moderated a little in the east of the country for February, partly in response to flooding rainfall in tropical Queensland. Even so, the national mean temperature will come in around 1.4℃ above average, making this February likely to be the fourth or fifth warmest on record.

…and very dry

Australia has seen dry summers before and many of these have been notably hot. The summers of 1972–73 and 1982–83 – which featured mean temperatures 0.90℃ and 0.92℃ above average, respectively – both came during the latter stages of significant droughts, and were both records at the time.

As the State of the Climate 2018 report outlines, Australia has warmed by just over 1℃ since 1910, with most warming occurring since 1950. This warming means global and Australian climate variability sits on top of a higher average temperature, which explains why 2018-19 was warmer again.

A major rain event affected tropical Queensland during late January to early February, associated with a slow-moving monsoonal low. Some sites had a year’s worth of rain in a two-week period, including Townsville Airport which had 1,257mm in ten days. Many Queenslanders affected by this monsoonal low went from drought conditions to floods in a matter of days. Flooding was severe and continues to affect rivers near the Gulf of Carpentaria, as well as some inland rivers which flow towards Kati Thanda–Lake Eyre.

Preliminary summer 2018–19 rainfall deciles.
Bureau of Meteorology

The outlook for autumn

Spring 2018 saw a positive Indian Ocean Dipole which faded in early summer. At the start of summer sea surface temperature anomalies in the central Pacific exceeded 0.8℃, which is the typical threshold for El Niño affecting the oceans, but these declined as summer progressed. Combined with a lack of coupling between the atmosphere and ocean, the El Niño–Southern Oscillation remained neutral, though normal rainfall patterns shifted to oceans to the north and east, leaving Australia drier as a result.

As we move into autumn, the El Niño–Southern Oscillation and Indian Ocean Dipole tend to have less influence at this time of year. The onset of new Indian Ocean Dipole or El Niño/La Niña events typically happens in late autumn or winter/spring.

Over recent years, autumn rainfall has also become less reliable, with declines in cool season rainfall in the southeast and southwest. Temperatures are also rising, in a local expression of the global warming trend.




Read more:
Explainer: El Niño and La Niña


The Bureau’s outlook for autumn shows high probabilities that day and night-time temperatures will remain above average for most of the country. We expect to see continued below-average rainfall in much of the east, where drought is currently widespread.

Looking to the winter, the Bureau’s ENSO Wrap-Up suggests the Pacific Ocean is likely to remain warmer than average. The potential for an El Niño remains, with approximately a 50% chance of El Niño developing during the southern hemisphere autumn or winter, twice the normal likelihood.

Rainfall outlook for autumn 2019.
Bureau of Meteorology


For more information watch BOM’s March–May 2019 Climate and Water Outlook video and subscribe to receive Climate Information emails.The Conversation

David Jones, Climate Scientist, Australian Bureau of Meteorology; Lynette Bettio, Senior Climatologist, Australian Bureau of Meteorology, and Skie Tobin, Climatologist, Australian Bureau of Meteorology

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Look up! Your guide to some of the best meteor showers for 2019


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The 2018 Geminids meteor shower recorded over two very cold hours on the slope of Mount Lütispitz, Switzerland.
Flickr/Lukas Schlagenhauf, CC BY-ND

Jonti Horner, University of Southern Queensland and Tanya Hill, Museums Victoria

The year gets off to a bang with the Quadrantids, the first of the annual big three meteor showers. Active while the Moon is new, it gives northern hemisphere observers a show to enjoy during the cold nights of winter. Sadly, the shower is not visible from southern skies.

The other two members of the big three — the Perseids and Geminids — are not so fortunate this year, with moonlight set to interfere and reduce their spectacle.

So, with that in mind, where and when should you observe to make the best of 2019’s meteoric offerings? Here we present the likely highlights for this year – the showers most likely to put on a good show.




Read more:
Explainer: why meteors light up the night sky


We provide details of the full forecast activity period for each shower, and the forecast time of maximum. We also give sky charts, showing you where best to look, and give the theoretical peak rates that could be seen under ideal observing conditions – a number known as the Zenithal Hourly Rate, or ZHR.

It is important to note that the ZHR is the theoretical maximum number of meteors you would expect to see per hour for a given shower, unless it were to catch us by surprise with an unexpected outburst!

In reality, the rates you observe will be lower than the ZHR – but the clearer and darker your skies, and the higher the shower’s radiant in the sky, the closer you will come to this ideal value.

For any shower, to see the best rates, it is worth trying to find a good dark site (the darker the better) – far from streetlights and other illuminations. Once you’re outside, give your eyes plenty of time to adapt to the dark – half an hour should do the trick.

Showers that can only really be seen from one hemisphere or the other are denoted by either [N] or [S], while those that can be seen globally are marked as [N/S].

You can download this ics file and add to your calendar to stay informed on when the meteor showers are due.

Quadrantids [N]

Active: December 28 – January 12

Maximum: January 4, 2:20am UT = 2:20am GMT = 3:20am CET

ZHR: 120 (variable, can reach ~200)

Parent: It’s complicated (comet 96P/Macholz and asteroid 2003 EH1)

Despite being one of this year’s three most active annual showers, the Quadrantids are often overlooked and under-observed. This is probably the result of their peak falling during the depths of the northern hemisphere winter, when the weather is often less than ideal for meteor observations.

For most of the fortnight they are active, Quadrantid rates are very low (less than five per hour). The peak itself is very short and sharp, far more so than for the year’s other major showers. As a result, rates exceed a quarter of the maximum ZHR for a period of just eight hours, centred on the peak time.

The Quadrantid radiant lies in the northern constellation Boötes, relatively near the tail of Ursa Major, the Great Bear. The radiant is shown here at around midnight, local time, as it begins to climb higher in the northeastern sky.
Museums Victoria/Stellarium, Author provided

The Quadrantid radiant lies in the northern constellation Boötes, the Herdsman, and is circumpolar (never sets) for observers poleward of 40 degrees north. As a result, observers in northern Europe and Canada can see Quadrantids at any time of night. The radiant is highest in the sky (and the rates are best) in the hours after midnight.

For this reason, this year’s peak (at 2:20am UT) is best suited for observers in northern Europe – and given that peak rates can exceed 100 per hour, it is certainly worth setting the alarm for, to get up in the cold early hours, and watch the spectacle unfold.

This false-color composite image shows a combination of Quadrantid and non-Quadrantid meteors streaking through the skies over NASA’s Marshall Space Flight Center, in the US, on the night of January 3-4, 2012.
NASA/MSFC/Meteoroid Environments Office/Danielle Moser and Bill Cooke, CC BY-NC

Alpha Centaurids [S]

Active: January 31 – February 20

Maximum: February 8, 1:00pm UT = February 8, 9pm (WA) = February 8, 11pm (QLD) = February 9, 12am (NSW/ACT/Vic/Tas)

ZHR: Variable; typically 6, but can exceed 25

Parent: Unknown

The Alpha Centaurids are a minor meteor shower, producing typical rates of just a few meteors per hour. But they are famed as a source of spectacular fireballs for southern hemisphere observers and so are worth keeping an eye out for in southern summer skies.

Alpha Centaurids are fast meteors, and are often bright. As with most showers that are only visible from the southern hemisphere, they remain poorly studied. Though typically yielding low rates, several outbursts have occurred where rates reached or exceeded 25 per hour.

The shower’s radiant lies close to the bright star Alpha Centauri – the closest naked-eye star to the Solar System and the third brightest star in the night sky.

The Alpha Centaurids are well placed for the southern hemisphere. This view from Brisbane around the time of maximum activity.
Museums Victoria/Stellarium

Alpha Centauri is just 30 degrees from the south celestial pole. As a result, the radiant essentially never sets for observers across Australia. The best rates will be seen from late evening onward, as the radiant rises higher into the southern sky.

This year, the peak of the Alpha Centaurids coincides with the New Moon, making it an ideal time to check out this minor but fascinating shower.

Eta Aquariids [S preferred]

Active: April 19 – May 28

Maximum: May 6, 2pm UT = May 6, 10pm (WA) = May 7, 12am (QLD/NSW/ACT/Vic/Tas)

ZHR = 40+

Parent: Comet 1P/Halley

The Eta Aquariids are possibly the year’s most overlooked treat, particularly for observers in the southern hemisphere. The first of two annual showers produced by comet 1P/Halley, the Eta Aquariids produce excellent rates for a whole week around their peak.

The radiant rises in the early hours of the morning, after the forecast maximum time, and best rates are seen just as the sky starts to brighten with the light of dawn. It can be well worth rising early to observe them, as rates can climb as high as 40 to 50 meteors per hour before the brightening sky truncates the display.

Look for the Eta Aquariids before sunrise and catch Venus and Mercury too.
Museums Victoria/Stellarium

Eta Aquariid meteors are fast and often bright, and the shower regularly rewards those who are willing to rise early. Spectacular Earth-grazing meteors that tear from one side of the sky to the other can be seen shortly after the radiant rises above the horizon.

This year conditions are ideal to observe the shower, with New Moon falling on May 4, just two days before the forecast maximum. As a result, the whole week around the peak will be suitable for morning observing sessions, giving observers plenty of opportunity to see the fall of tiny fragments of the most famous of comets.

Southern Delta Aquariids, Piscis Austrinids and Alpha Capricornids [N/S; S favoured]

Active: Early-July to Mid-August

Maximum: July 28 – 30

Combined ZHR: 35

Parent: Comet 96P/Macholz (Southern Delta Aquariids); Unknown (Piscis Austrinids); Comet 169P/NEAT (Alpha Capricornids)

In most years, the approach of August is heralded by keen meteor observers as the build up to the Perseids – the second of the year’s big three showers. This year, moonlight will interfere, spoiling them for most observers.

But this cloud comes with a silver lining. A fortnight or so before the peak of the Perseids, three relatively minor showers come together to provide an excellent mid-winter show for southern hemisphere observers. This year, the Moon is perfectly placed to allow their observation.

These three showers – the Southern Delta Aquariids, Alpha Capricornids and Pisces Austrinids – favour observers in the southern hemisphere, though they can also be observed from northern latitudes.

Regardless of your location, the best rates for these showers are seen in the hours after midnight. Reasonable rates begin to be visible for southern hemisphere observers as early as 10pm local time.

The radiants of the Southern Delta Aquariids, Alpha Capricornids and Piscis Austrinids ride high in the southern hemisphere sky around local midnight.
Museums Victoria/Stellarium
For northern hemisphere observers, the radiants of the same three showers sit low to the horizon around local midnight.
Museums Victoria/Stellarium

The Southern Delta Aquariids are the most active of the three, producing up to 25 fast, bright meteors per hour at their peak, which spans the five days centred on July 30.

The Alpha Capricornids, by contrast, produce lower rates typically contributing just five meteors per hour. But where the Southern Delta Aquariids are fast, the Alpha Capricornids are very slow meteors and are often spectacular.

Like the Alpha Centaurids, in February, they have a reputation for producing large numbers of spectacular fireballs. This tendency to produce meteors that are both very bright and also slow moving makes them an excellent target for astrophotographers, as well as naked-eye observers.

An Alpha Capricornid meteor captured among the star trails in 2013.
Flickr/Jeff Sullivan, CC BY-NC-ND

Taurids [N/S]

Active: September 10 – December 10

Maxima: October 10 (Southern Taurids); November 13 (Northern Taurids)

ZHR: 5 + 5

Parent: Comet 2P/Encke

The Taurids are probably the most fascinating of all the annual meteor showers. Though they only deliver relatively low rates (approximately five per hour from each of the two streams, north and south), they do so over an incredibly long period – three full months of activity.

In other words, the Earth spends a quarter of a year passing through the Taurid stream. In fact, we cross the stream again in June, when the meteors from the shower are lost due to it being exclusively visible in daylight.

So a third of our planet’s orbit is spent ploughing through a broad stream of debris, known as the Taurid stream. In total, the Taurid stream deposits more mass of meteoric material to our planet’s atmosphere than all of the other annual meteor showers combined.

So vast is the Taurid stream that there is speculation that it originated with the cataclysmic disintegration of a super-sized comet, thousands or tens of thousands of years in the past, and that the current shower is a relic of that ancient event.

The two Taurid radiants, as seen from northern Europe before dawn [Paris 6:30am, October 10]
Museums Victoria/Stellarium
The November maximum will be hindered by the Moon, this view as seen from Melbourne during the early hours of November 13.
Museums Victoria/Stellarium

Taurid meteors are slow, and are often spectacularly bright. Like the Alpha Capricornids, they have a reputation for producing regular fireballs, making them another good target for the budding astrophotographer.

Rather than having a single, sharp peak, Taurid activity stays at, or close to, peak rates for the best part of a month, between the maxima of the northern and southern streams, meaning that it is always possible to find some time when moonlight does not interfere to observe the shower.

Geminids [N/S]

Active: December 4 – December 17

Maximum: December 14, 6:40pm UT = December 15, 4:40am (QLD) = December 15, 5:40am (NSW/ACT/Vic/Tas)

ZHR: 140+

Parent: Asteroid 3200 Phaethon

Another of the big three annual meteor showers, the Geminids are probably the best, with peak rates in recent years exceeding 140 meteors per hour.

A composite image of the Geminids shower from the vantage point of Johnson Space Center, US.
NASA/Lauren Harnett, CC BY-NC

The Geminids are visible from both hemispheres – although the radiant rises markedly earlier for northern observers. Even in the south of Australia, the radiant rises well before midnight, giving all observers the rest of the night to enjoy the spectacle.

The Moon interferes with the Geminids, which radiate close to the bright star Castor. This view is from Perth in the hours before sunrise.
Museums Victoria/Stellarium

Moonlight will seriously interfere with the peak of the shower this year, washing out the fainter meteors, with the result that observed rates will be lower than the ZHR might otherwise suggest.

But the shower regularly produces abundant bright meteors, and yields such high rates that it is still well worth checking out, even through the glare of the full Moon.

Ursids [N]

Active: December 17 – December 26

Maximum: December 23, 3:00am UT

ZHR: 10+

Parent: Comet 8P/Tuttle

The final shower of the year – the Ursids – is a treat for northern hemisphere observers alone. Much like the shower that started our journey through the year, the Quadrantids, the Ursids remain poorly observed, often lost to the bleak midwinter weather that plagues many northern latitudes.

But if skies are clear the Ursids are visible throughout the night, as their radiant lies just 12 degrees from the north celestial pole. As such, they make a tempting target for observers to check out in the evening, even if the radiant is at its highest in the early hours of the morning.

Most years, the Ursids are a relatively minor shower, with peak rates rarely exceeding ten meteors per hour. They have thrown up a few surprises over the past century, with occasional outbursts of moderately-fast meteors yielding rates up to, and in excess of, a hundred meteors per hour.

The Ursid radiant, in the constellation Ursa Minor, is circumpolar for almost the entire northern hemisphere, as it lies just 12 degrees from the north celestial pole. It is shown here as it would be seen at 11pm from near Tokyo, Japan.
Museums Victoria/Stellarium

While no such outburst is predicted for 2019, the Ursids have proven to be a shower with a surprise or two left to show and so may just prove to be an exciting way to end the meteoric year.


If you have a good photo of any of this year’s meteor showers that you’d like to share with The Conversation’s readers then please send it to readerspic@theconversation.edu.au. Please include your full name and the location the photo (or any composite) was taken.The Conversation

Jonti Horner, Professor (Astrophysics), University of Southern Queensland and Tanya Hill, Honorary Fellow of the University of Melbourne and Senior Curator (Astronomy), Museums Victoria

This article is republished from The Conversation under a Creative Commons license. Read the original article.