Cleaning, but safely! Cocoons protect sensitive ant brood during toxic disinfection

Date:  October 9, 2018

Source:  Institute of Science and Technology Austria

Ants are neat: when they move into a new nest box, they spend the first days cleaning it thoroughly, like us humans getting out the cleaning bucket when moving into a new home. Despite keeping the nest clean, using poison within the nest is dangerous and can kill unprotected brood. However, the silk cocoon that surrounds the ant's sensitive pupae protects them from any harmful effects, as Sylvia Cremer from the Institute of Science and Technology Austria (IST Austria), and her team, including first author doctoral student Christopher Pull -- now a postdoc at the Royal Holloway University London (RHUL) -- show in today's edition of Current Biology.

Many ants produce highly acidic chemicals from specialized glands in their body. For a long time, researchers assumed that ants only spray this poison, which is made mostly of formic acid, to fight other ants and would-be predators. But in two studies published in 2013 and 2018, Sylvia Cremer and her team showed that ants use acidic chemicals to disinfect nest-mates contaminated and infected with pathogens. In the current study, published by Pull et al., Cremer's research team show that Lasius neglectus ants also spray their nests prophylactically with their acidic poison, likely ensuring that the nest is clean for first-time occupancy. But, given the poison doubles-up as a chemical weapon, the use of the poison within the nest raises further questions, as Sylvia Cremer explains: "How can ants spray this aggressive acid in their nest, whilst leaving their sensitive brood in the acidic fog?" Whilst adult ants are protected from the poison by a thick skin (the cuticle) and eggs by a protective "shell" (the corion), the cuticle of the pupae is thin and fragile, and so very susceptible to damage. However, pupae of the Lasius neglectus species are also covered in a silk cocoon, which Pull et al hypothesized may offer them protection.

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Food-carrying ants use collective problem solving to get through or around obstacles

Food-fragment size controls switching between two different modes of movement

Date:  May 10, 2018

Source:  PLOS

Summary:

Ants working together to carry a large piece of food get around obstacles by switching between two types of motion: one that favors squeezing the morsel through a hole and another to seek a path around the barrier.

Ants working together to carry a large piece of food get around obstacles by switching between two types of motion: one that favors squeezing the morsel through a hole and another to seek a path around the barrier. Jonathan Ron of the Weizmann Institute, Israel, and colleagues present these findings in PLOS Computational Biology.

When carrying large food items such as worms or maggots, ants often face obstacles in their path. The cooperating ants need to reach a consensus and decide on a new route to their nest. Previous studies have shown that alternating, side-to-side motions can help ants get around an obstacle, but what drives this motion and determines whether it will happen has been unclear.

Ron and colleagues built a mathematical model that simulates ants' behavior when facing a rigid barrier with a narrow hole. The simulations suggest that ants randomly switch between two modes of motion, one in which they dwell near the hole, providing a chance to pass food through it, and another in which sideways motions allow them to seek their way around the obstacle. Switching between modes ensures the ants do not get stuck in a single mode without finding a solution.

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New ant species from Borneo explodes to defend its colony

Date:  April 19, 2018

Source:  Pensoft Publishers

Summary:

When their colony is threatened by an intruder, workers of a newly discovered species of ant can actually tear their own body apart, in order to release toxins and either kill or hold off the enemy. The new species is the first of the so-called 'exploding ants' to be described since 1935.

Amongst the countless fascinating plants and animals inhabiting the tropical rainforests of Southeast Asia, there are the spectacular "exploding ants," a group of arboreal, canopy dwelling ants nicknamed for their unique defensive behaviour.

When threatened by other insects, minor workers can actively rupture their body wall. Apart from leading to the ants' imminent death, the "explosion" releases a sticky, toxic liquid from their enlarged glands, in order to either kill or hold off the enemy.

Curiously enough, while these ants' peculiar behaviour was first mentioned in distant 1916, no new species have been formally described since 1935, due to insufficient evidence. Instead, scientists used to simply refer to them as the members of a remarkable species group -- Colobopsis cylindrica, better known as "the exploding ants."

That was until an interdisciplinary research team from Austria, Thailand and Brunei came together led by their shared fascination with these insects and their extraordinary mechanism of self-sacrifice (also called autothysis) in 2014. Thus, entomologists, botanists, microbiologists, and chemists from the Natural History Museum Vienna, Technical University Vienna, IFA Tulln and Universiti Brunei Darussalam together identified roughly 15 separate species of exploding ants, with one of them now described as new to science in the open access journal ZooKeys.

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New light shed on antibiotics produced by ants

Date:  February 7, 2018

Source:  North Carolina State University

Summary:

Ants, like humans, deal with disease. To deal with the bacteria that cause some of these diseases, some ants produce their own antibiotics. A new comparative study identified some ant species that make use of powerful antimicrobial agents -- but found that 40 percent of ant species tested didn't appear to produce antibiotics. The study has applications regarding the search for new antibiotics that can be used in humans.

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Heat-loving Australian ants believe in diversity, hint 74 species new to science

Date:  September 21, 2017

Source:  Pensoft Publishers

Summary:

A genus of Australian ants, many of whose members prefer to forage in blistering temperatures of up to 50°C (122°F), is revised to include 74 new species. The ants include seed-eaters, ant and termite raiders, 'honeypot ants' that store nectar and honeydew, and numerous others whose biology is not yet understood. Some are bizarre: one species has eyes like inverted ice-cream cones.

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Scientists show molecular basis for ants acting as 'bodyguards' for plants

Date: September 18, 2017

Source: University of Toronto

Summary:

Though you might not think of ants as formidable bodyguards, some do an impressive job protecting plants from enemies. Examing the relationship between the Amazon rainforest plant Cordia nodosa in Peru and the ant species Allomerus octoarticulatus, scientists found the degree to which the ants express two genes significantly impacts the amount of protection they provide to their hosts.

     

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Meet the vampire ant from hell with huge jaws and a metal horn

10 September 2017

By Josh Gabbatiss

A newly discovered species of prehistoric “hell ant” had anatomy that lived up to its demonic name, including a lethal feeding apparatus reinforced with metal.

Hell ants are an extinct lineage from the Cretaceous Period. Instead of regular mouthparts, they had upward-facing blades.

No living species have such facial anatomy. However, the hairs around hell ants’ mouths are reminiscent of hairs on modern trap-jaw ants that cause their mouths to snap shut when triggered. This has led to speculation that the hell ants’ mouthparts worked in a similar way.

Some also had a horn-like appendage that jutted out over their tusk-like mandibles. This includes the new species, Linguamyrmex vladi, which Phillip Barden at the New Jersey Institute of Technology in Newark and his colleagues found preserved in 98-million-year-old amber.

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Say hello to the 3-D Obama ant

Three new ant species named in honor of key figures in conservation -- Barack Obama, Ken Saro-Wiwa, and E.O. Wilson -- are immortalized as 3-D virtual avatars

Date: August 30, 2017

Source: Okinawa Institute of Science and Technology (OIST) Graduate University

Summary:

Three new ant species named in honor of key figures in conservation -- Barack Obama, Ken Saro-Wiwa, and E.O. Wilson -- are immortalized as 3-D virtual avatars.

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Decoding ants' coat of many odors

Date:  July 10, 2017

Source:  Vanderbilt University

Summary:  Biologists report a major advance in deciphering the molecular genetics underlying the ant's high-definition sense of smell, an ability that has allowed them to create the most complicated social organization on earth next to humans.

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Watch this spider walk just like an ant

By Andrew WagnerJul. 11, 2017 , 7:15 PM

In order to avoid spider-loving predators, the jumping spider Myrmarachne formicaria has evolved to look like an ant. But a new study suggests it has learned to walk like an ant, too. The arachnid walks back and forth in a winding wave motion that looks like an ant following a trail, researchers report today in the Proceedings of the Royal Society B. Scientists previously thought that these antlike spiders don’t use their front legs at all when walking, constantly raising them up as pantomime antennae. However, when viewed in slow motion with a high-speed camera, the spiders move using all eight legs, only raising their forelimbs whenever they take a pause. These pauses appear to be consistently spaced out and timed just long enough to cement the antennae illusion for any predators that may be watching.

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Cannibal 'T. Rex' Ants Seen Live for 1st Time Ever (and They're Shy)

By Stephanie Pappas, Live Science Contributor | May 16, 2017 02:14pm ET 

An ant named after the fierce, carnivorous dinosaur Tyrannosaurus rex has been observed alive for the first time — and it failed to live up to the dinosaur's reputation.

Tyrannomyrmex rex is a timid, finicky eater, new research finds. The ants can, however, turn to cannibalism in times of need.

Until now, these Asian ants were a complete mystery to science, despite being discovered more than 20 years ago. No one had ever collected more than a single specimen, and no one had ever observed a T. rex ant alive for an extended period of time. So when biologist Mark Wong stumbled across a colony of T. rex ants while conducting an ant diversity survey in Singapore, he knew he had something important.

He and his colleague Gordon Yong from the National University of Singapore carefully collected the colony, which consisted of 13 workers, as well as eggs, larvae and pupae (the liminal stage between larva and adulthood). They then observed the ants in an attempt to figure out what makes them tick. Because the study is the first of its kind, everything the researchers discovered is new, Wong told Live Science.

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Diverse populations make rational collective decisions

Date: May 17, 2017

Source: Hokkaido University

Understanding how ant colonies make collective decisions could provide insight into the functioning of the human brain.

Yes/no binary decisions by individual ants can lead to a rational decision as a collective when the individuals have differing preferences to the subject, according to research recently published in the journal Royal Society Open Science. This binary mechanism of decision-making could provide a basis for understanding how neurons in the human brain, which also make binary choices, work together.

Honey bees are known to "dance" with varying levels of enthusiasm depending on the quality of nectar they find. The more attractive the nectar is, the stronger they dance, appealing to other members. As a result, the majority of the members, and later the entire colony, gather to the better option. However, this mechanism doesn't explain how a collective rationality within the brain is made because neurons can only make binary decisions.

Tatsuhiro Yamamoto and Eisuke Hasegawa of Hokkaido University's Laboratory of Animal Ecology set up six experimental colonies of 56 Myrmica kotokui ants. Each individual ant was marked to distinguish them from one another.

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