Category: Ants

Fijian ants grow their own plant cities and farm tropical fruits

On By A.P.In AntsLeave a comment

By Alice Klein

Ants beat us to it. A Fijian ant first started planting fruit crops 3 million years ago, long before human agriculture evolved.

The ant – Philidris nagasau – grows and harvests Squamellaria fruit plants that grow on the branches of various trees.

First, the ants insert seeds of the fruit plant in the cracks in tree bark. Workers constantly patrol the planting sites and fertilise the seedlings, probably with their faeces.

As the plants grow, they form large, round hollow structures at their base called domatia that the ants live in instead of building nests. When the fruit appears, the ants eat the flesh and collect the seeds for future farming.

Guillaume Chomicki at the University of Munich, Germany, and his colleagues discovered that each ant colony farmed dozens of Squamellaria plants at the same time, with trails linking each thriving hub. The connected plant cities often spanned several adjacent trees.

The researchers found that Squamellaria plants are completely dependent on the ants to plant and fertilise their seeds. At the same time, Philidris nagasau ants cannot survive without the food and shelter provided by the plants. The Fijian phenomenon is the first documented example of ants farming plants in a mutually dependent relationship.

Trees in nearby Australia have been observed with similar-looking ant-filled plants growing along their branches, but no one has known why, says Simon Robson at James Cook University in Australia. The plants are from the same family as Squamellaria, suggesting they have the same symbiotic farming relationship with ants.

Chomicki’s team also conducted a genetic analysis to study the history of the Fijian ant-plant interactions. The results showed that the ants lost their ability to build nests around 3 million years ago, at the same time as the plants developed roots that could grow in bark. This signals the beginning of the mutual relationship, which emerged when Fiji and Australia were still connected.

Brainy ants
Only a handful of other species have been found to farm their food. For example, Yeti crabs cultivate bacteria on their claws and sloths grow algae gardens on their fur. Ants have been known to cultivate fungi, but this is the first time they have been found to plant crops in such a mutualistic manner.

The fact that ants have developed such sophisticated food production skills confirms the impressive teamwork of ants, says Kirsti Abbott at the University of New England, Australia.

“Ants are a lot smarter than we think they are – we call them superorganisms because they form networks that are much like our brains,” she says. “The information flow among ant colonies is just insane compared to human social systems, so this finding does not surprise me in the slightest.”

Journal reference: Nature Plants, DOI: 10.1038/nplants.2016.181

https://www.newscientist.com/article/2113410-fijian-ants-grow-their-own-plant-cities-and-farm-tropical-fruits/

First-Ever In-Home Toilets Spotted for Ants

On By A.P.In AntsLeave a comment

ants

Other than dung beetles, most animals try their best to avoid poop. Humans typically build entire rooms designed to flush the stuff away. The ick factor evolved for good reason: fecal matter is a great place for microorganisms to live and grow, some of which can lead to serious infection and illness.
Like us, many insects that live in colonies have evolved ways of keeping their nests and hives sanitary. Honeybees perform so-called defecation flights, in which they leave the nest to do their business. Some ants, like leaf-cutters, use their feces as manure for gardens that grow fungal food, but only certain “sanitation workers” are permitted to handle it. Ants in general are well known for their cleanliness—disposing of the dead outside the nest and leaving food scraps and other waste in special refuse chambers.

Thus, University of Regensburg biologist Tomer J. Czaczkes was surprised when he noticed dark patches accumulating in the corners of the white plaster nests in which his black garden ants, Lasius niger, lived. Over seven years of observations, he became convinced the dark patches were made of feces.
To confirm his suspicion, Czaczkes added artificial coloring to the ants’ food for 21 colonies. Sure enough, the dark patches started showing up in brilliant shades of red and blue. Because the piles of ant poo never contained food scraps, corpses or other debris, Czaczkes and his colleagues conclude that referring to these spots as “toilets” is apt. The results were detailed in the February issue of PLOS ONE.

No one is sure why black garden ants keep their feces inside the nest, especially given that Formicidae are otherwise fastidious housekeepers. Perhaps it is used for defense, for territory demarcation or as a building material. Or it could serve as a source of salt or other nutrients. Another possibility, according to Czaczkes, is that the waste is stored precisely because it is stinky. “Ants tell friend from foe apart by their smell,” he explains. “Perhaps newly emerged ants go to the toilet and sort of ‘bathe’ in it, to pick up the colony smell quickly.” Each explanation is plausible, so more research will be necessary to determine the best one.

“The next obvious step is a lot of boring observation, where I hope to catch the ants using the toilets,” he says. To covertly watch them do their business, Czaczkes will have to make nests with see-through lids and work under red light, which the ants cannot see. Onward, entomology.

http://www.scientificamerican.com/article/first-ever-in-home-toilets-spotted-for-ants/

Secrets of Ant Rafts Revealed

On By A.P.In ant raft, Ants, Da Brayn, David Hu, fire ant, Georgia Institute of Technology, Journal of Experimental Biology, Nature, Paul Foster, Radhika Nagpal, University of MichiganLeave a comment

To negotiate floods and cross streams, fire ants band together — literally — linking together to form rafts and bridges in a feat of social cooperation and biophysics. Now, engineers have made a close study of the ants’ architectural technique, pointing the way towards new approaches for robot designers and materials scientists.

To understand the properties of the ant structures, David Hu, a mechanical engineer at the Georgia Institute of Technology in Atlanta, sought to observe not just the surface of the ant clumps but the structure and joints underneath.

First, Hu and his team collected ant colonies — shovelling them, dirt and all, into buckets. After separating out the ants from the dirt, they then put 100 or so ants into a cup and swirled, causing the ants to form into a ball (no water necessary — they come together almost like dough). The researchers then froze the ball with liquid nitrogen so they could examine it in a micro-computed-tomography scanner to come up with a 3-D picture.

But the heat of the scanner melted the ball into a heap of dead ants. After months of experimenting with techniques to keep it together, lead author Paul Foster, now at the University of Michigan, found an unlikely source of inspiration in crack cocaine — specifically, in a method of vaporizing the drug to inhale it. “We did the same process — not with crack, but glue,” says Hu, adding that the authors decided against calling it the ‘crack-pipe method’ in their paper. The researchers heated the glue in an aluminium pot over a flame, with the frozen ant ball suspended on mesh above. The glue vapour rose and lightly coated the ants.

Social networking
Hu and his team found that the ants had grabbed hold of one another with adhesive pads on their legs, which they stretched out to create pockets of air. They also tended to orient themselves perpendicularly to one another, distributing their weight and creating a light, buoyant structure. The formation seems to take advantage of the ants’ different sizes, with smaller ants slotting neatly in between larger ones to add more connections. Each ant averaged 14 connections to fellow ants. The study is published today in the Journal of Experimental Biology.

Radhika Nagpal, who creates biologically inspired robots at Harvard University in Cambridge, Massachusetts, says that Hu’s ants could make great models for modular robots. “There’s lots of interesting outcomes of this work,” she says. “Imagine robots that need to construct a barrier or patch a hole during a disaster response.”

Rather than building one perfect robot, she notes, designers are increasingly exploring building a “colony of simple robots that use their bodies and the connections between them to build new structures.” Most projects in this vein have used geometric robots with precise connections. But ants do not create a perfect lattice, suggesting a sloppier, more organic approach in which robot shapes are varied and irregular and connections between them are inexact, Nagpal says. Hu thinks that the properties of ant structures might not only inform the design of robot swarms, but also the design of ‘smart’ materials that assemble themselves in response to temperature, light or other variables.

Hu is working on getting larger ant structures — recognizably distinct as bridges, rafts and other forms — into a bigger scanner to begin detailing the properties of the different functional shapes. And once they are frozen and coated in glue, they will last forever, Hu says. “One day,” he jokes, “we will have a miniature museum of ant structures.”

Thanks to Da Brayn for bringing this to the attention of the It’s Interesting community.

http://www.scientificamerican.com/article/secrets-of-ant-rafts-revealed/

Crazy ants from South America use a secret weapon against fire ant venom to aid their invasion of the southern U.S

On By A.P.In Ants, crazy ants, Ed LeBrun, fire ant, LiveScience, Nature, Science, Tanya Lewis, University of Texas, University of Texas at AustinLeave a comment

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By Tanya Lewis, LiveScience

All over the southern United States, miniature foes are engaging in fierce battle. Invasive “crazy ants” have been displacing fire ants, and a curious defensive strategy may be behind the crazy ants’ bold takeover.

Fire ants pack potent venom that kills most ants that come into contact with it. But when crazy ants get stung, they secrete a substance and rub it all over themselves to neutralize the venom, new research finds.

This detoxifying behavior — the first example of an insect capable of detoxifying another’s venom — may be the reason crazy ants have been able to compete with the venomous fire ants, according to the study detailed online on Feb. 13 in the journal Science.

“As this plays out, unless something new and different happens, crazy ants are going to displace fire ants from much of the southeastern U.S. and become the new ecologically dominant invasive ant species,” study leader Ed LeBrun, a researcher at the University of Texas at Austin, said in a statement.

Fire ants (Solenopsis invicta) invaded the U.S. South in the 1930s, hailing from their native South America home. Another South American species, tawny (or raspberry) crazy ants (Nylanderia fulva) — named for their color and their quick, erratic movements — invaded Texas and Florida in the early 2000s, and have been steamrolling fire ant populations in the South ever since.

When fire ants attack, they dab their enemies with powerful venom that usually kills other insects. But LeBrun’s team noticed that after crazy ants were dabbed with the venom, they would stand on their hind and middle legs, curl their abdomens — which are covered in glands that secrete formic acid — and smear the acid all over their bodies.

To study how the detoxing substance worked, the researchers sealed off the crazy ants’ glands with nail polish and then placed the ants in a container with red fire ants. Only about half of these crazy ants survived after being dabbed with venom by the fire ants, compared with 98 percent of unpainted crazy ants.

The researchers aren’t sure exactly how the formic acid protects crazy ants from the fire ant venom. The acid may protect the crazy ant by destroying venom proteins and preventing them from penetrating the ant’s exoskeleton.
Crazy ants and fire ants are both native to northern Argentina, Paraguay and southern Brazil, where their territories overlap. The crazy ants likely evolved their detoxifying behavior alongside their venomous neighbors, the researchers said.

In contrast to fire ants, crazy ants don’t confine themselves to mounds in the garden. They crawl inside homes and even swarm inside electronic appliances — shorting out phones, air conditioners and other devices.

“When you talk to folks who live in the invaded areas, they tell you they want their fire ants back,” LeBrun told Live Science previously.

Crazy ants don’t have as painful a sting as fire ants, but they multiply more quickly and don’t eat the same ant poison bait, scientists say. Fortunately, the crazy ant invasion moves slowly, advancing only about 600 feet (180 meters) per year, except if transported in potted plants or vehicles. LeBrun recommends that people check plants for ant nests before buying them, and check their cars before traveling if they live in crazy ant-infested areas.

Other than human activities, geology and climate are the only factors standing in the way of these determined insects, which continue their relentless takeover of the South.

http://www.mnn.com/earth-matters/animals/stories/crazy-ants-use-a-secret-weapon-to-aid-their-invasion-of-the-southern

Formic acid in flying ants is making seagulls intoxicated

On By A.P.In Ants, seagullLeave a comment

secpic_seagull1_b123370404311

Seagulls in southwest England are getting intoxicated from consuming flying ants, brazenly stealing food out of residents’ hands, flying directly into buildings and failing to get out of the way of cars. Apparently, the birds are becoming inebriated from the formic acid in the ants’ bodies, which lowers their inhibitions and disrupts their coordination, similar to the effect of alcohol.

Hot weather has helped spawn large populations of ants, upon which the seagulls feed. “That isn’t so good for the birds – it leaves them a bit drunk,” Rebecca Nesbit, and entomologist with the Society of Biology, said.

Formic acid is likely the reason for a strange bird behavior known as ‘anting,’ in which the birds thrash around, covering themselves in ants. The formic acid may help the birds repel parasites.

http://www.livescience.com/38336-seagulls-drunk-on-ants.html

Giant Ant Hill Excavated

On By A.P.In Ants, NatureLeave a comment

Ever wonder what the interior of a giant ant hill looks like? Wonder no more, as a group of researchers filled a giant ant hill with 10-tons of concrete and then conducted an excavation.

Beneath the surface, the megalopolis spans 50-square-meters and goes 8-meters into the earth.

And here’s the full show on Ants.  Pretty incredibly stuff.

Thanks to Kebmodee for bringing this to the attention of the It’s Interesting community.