The many-times-magnified photos of the Nikon Small World photomicrography contest entrance us year after year, with mesmerizing close-ups of nature’s microscopic marvels. Now, in the first Small World in Motion movie competition, we get to see the world’s wee wonders in action. The three winning films and eleven honorable mentions chronicle circulating blood, budding yeast, gestating eggs, and more.
First Place: This time-lapse video, at 10x magnification, traces the path of ink injected into an artery of a three-day-old chick embryo. As the ink spreads through the chick’s vascular system, the branching blood vessels and beating heart become clearly visible.
We at DISCOVER have always loved the terrifying specter of zombie animals controlled by menacing wasps, worms, and barnacles. This week there’s a new terror on the loose: Four newly found fungi that grow stalks right through the head of zombie ants in the Brazilian rainforest.
No glory for Glory: The NASA climate mission we covered last week—which was to study the interaction of the sun’s radiation, aerosols, and greenhouse gases in the atmosphere—ended in failure as it did not reach orbit in its launch attempt today.
It’s not Mega Shark vs. Giant Octopus, but a paleontologist’s research suggests that the story of North American survival long ago may have been bison v. mammoth. Eric Scott says the influx of bison from Eurasia may have doomed the saber-tooth cat, mammoth, and other megafauna that couldn’t compete.
It’s a classic David and Goliath story, except there are 90,000 Davids and they all have stings. On the African plains, the whistling-thorn acacia tree protects itself against the mightiest of savannah animals – elephants – by recruiting some of the tiniest – ants.
Elephants are strong enough to bulldoze entire trees and you might think that there can be no defence against such brute strength. But an elephant’s large size and tough hide afford little protection from a mass attack by tiny ants. These defenders can bite and sting the thinnest layers of skin, the eyes, and even the inside of the sensitive trunk. Jacob Goheen and Todd Palmer from Kenya’s Mpala Research Centre have found that ants are such a potent deterrent that their presence on a tree is enough to put off an elephant.
What does it take to be a long-living queen? Change your gene expression, say researchers who analyzed both worker ant and queen ant genes in two ant species–making the humble bug the second social insect (after the bee) to get sequenced.
Their results appear today in Science and suggest that epigenetic changes–molecular switches that alter gene expression–may mean the difference between the queen’s long life, and the workers’ short one. Epigenetic changes don’t actually modify the underlying genetic code, instead they’re carried out by mechanisms that act like on and off switches for genes. That could explain how a queen and worker ant can have the same genetic blueprints but very different lives.
“Ants are extremely social creatures and their ability to survive depends on their community in a very similar way to humans,” says [co-author Danny] Reinberg, who is also a member of the NYU Cancer Institute. “Whether they are workers, soldiers or queens, ants seem to be a perfect fit to study whether epigenetics influences behavior and aging.” [Arizona State University]
Here’s one that I didn’t touch on in DISCOVER’s creepy gallery of zombie animals controlled by mind-altering parasites: A parasitic fungus called Ophiocordyceps unilateralis that infects a plain old carpenter ant and takes over its brain, leading the ant to bite into the vein that runs down the center of a leaf on the underside. The ant dies shortly thereafter, but the fungus gains the nutrients it needs to grow this crazy stalk out of the ant’s body and release spores to create the next generation of ant-controlling fungi.
This cryptic cycle has been going on for at least 48 million years.
In a study forthcoming in Biology Letters, Harvard’s David Hughes argues that a fossilized leaf found in a fossil-rich part of Germany’s Rhine Rift Valley bears the scars of the ant’s trademark death bite. The ant bites down hard so the fungus will have a stable position when it grows a stalk out of the ant’s head. But even so, Hughes says, he doubted the mark would turn up in the fossil record—that is, until serendipity reared its random head:
Many children have a “bug period”–a time of life when bugs and creepy crawlies are a source of endless fascination and learning. Naturalist Edward O. Wilson jokes that unlike other kids, he never grew out of his bug period.
Luckily for this biologist, his lifelong passion for ants has yielded a career rich in accomplishment and accolades. He is not just the world’s preeminent expert on the social behavior of ants, but also the recipient of the National Medal of Science and two Pulitzer Prizes for nonfiction. Now, at the age of 80, Wilson has taken a stab at fiction. His first novel, Anthill, combines two of his greatest loves–his childhood home, Alabama, and the ants that have been his lifelong friends.
Described as an “six-legged Iliad,” Wilson’s Anthill draws parallels between human and ant societies. Though there are no ant symphony orchestras, secret police, or schools of philosophy, both ants and men conduct wars, divide into specialized castes of workers, build cities, maintain infant nurseries and cemeteries, take slaves, practice agriculture, and indulge in occasional cannibalism, though ant societies are more energetic, altruistic, and efficient than human ones [The New York Review of Books].
The book’s first and third sections deal with the adventures of an Alabama boy named Raphael Semmes Cody, called Raff. The boy grows up poking around the lush pine savanna of the Nokobee Tract; he’s drawn to its natural wonders, and uses the forest to escape from his parents’ toxic marriage. In this pristine woodland he literally leaves no stone unturned as he discovers the forest’s rich flora and fauna. Raff grows up and heads to Harvard to study law, returning later in life to protect the Nokobee from feckless developers. But fans of Wilson’s science will be most interested in the book’s middle section, where the author inserts a mini-novella describing the trials and tribulations of the ants living in the endangered forest.
In leafcutter ants and honeybees, it’s survival of the fittest sperm. Biologist Boris Baer, for a study out this week in Science, investigated these two species because of their peculiar sexual practices: In one day, the queen acquires all the sperm she’ll need to fertilize her eggs over the course of her lifetime. But in the race to be the top genetics-spreader, the males have evolved a dirty trick. Their seminal fluids actually do battle within the female’s reproductive tract.
To test out the idea, Baer and colleagues exposed the sperm of the bee and ant males to their own seminal fluid, and also to that of other males of the same species. The seminal fluid killed more than 50 per cent of the rival sperm within 15 minutes. “The males seemed to use the seminal fluid to harm the sperm,” says Baer [New Scientist]. When the team studied other organisms whose lifestyle didn’t depend on this kind of polyandry, they didn’t see the same effect.
A jumping spider that passes on eating ants in favor of leafy greens has just been described by scientists. The novel arachnid, named Bagheera kiplingi, is exciting because it is the first-known predominantly vegetarian spider; all of the other known 40,000 spider species are thought to be mainly carnivorous [BBC News]. The study was published in the journal Current Biology.
Found in Central America and Mexico, the order-defying jumping spider eats nutrient-rich structures called Beltian bodies, which are found on the tips of Acacia trees. Trees produce the bodies to feed ants that defend them, which is a textbook example of what’s called co-evolutionary mutalism, and one that B. kiplingi has evolved to exploit [Wired.com].Despite a primarily veggie diet, B. kiplingi actively hunts its green prey, which sounds bizarre, since the leaves can’t run away.The spiderfirst sits and stalks its target before it dodges through the ant defenses, snatches a Beltian body, and flees to safety.
In an ironic twist, the weaponry of the fire ants that have invaded the American South is also their potential downfall. Entomologists have found that the fire ants’ venom contains chemical compounds that attract their natural foes, the parasitic phorid flies that turn ants into zombies before decapitating them.
The invasive red fire ants first came from South America by boat, and from their original disembarkation point in Mobile, Alabama, they have spread across the South, from Texas to Maryland. Their painful stings and their habit of shorting out electrical equipment make them a serious pest to humans, and biologists have been attempting to control their numbers by importing and distributing the parasitic phorid flies. But until now, researchers didn’t know how the flies homed in on the ants. So researcher Henry Fadamiro hooked electrodes up to the antennae of flies to investigate which of several stimuli prompted nerves to fire. By exposing the antennae to extracts from different ant glands and body parts, the researchers determined that juice from the venom glands got antennae buzzing [Science News].
At some point in the first half of the 20th century, a couple of ants hitched a ride on a boat and ended up on Christmas Island, an Australian territory in the Indian Ocean. And so began the rampage of the “yellow crazy ants,” creatures that have been named one of the top 100 most invasive species in the world. On Christmas Island, scientists have now declared an “invasional meltdown” of the original ecosystem [Science News].
The latest evidence: The ants are so plentiful and bothersome that they’re preventing birds from feeding on berries, and the birds are therefore failing to disperse seeds around the island.
Researcher Dennis O’Dowd explains that the long-legged yellowish ants earned the named “crazy” because when they are disturbed they run around frenetically. O’Dowd says crazy ants form large super-colonies and cover ground and vegetation in densities of around 1000 ants per square metre. “These ants are three-dimensional foragers,” he says [ABC Science]. The ants can thickly cover the forest floor and swarm up vines and plants.
In a rare conservation success, a beautiful butterfly species that was headed for extinction has been brought back from the brink, thanks to careful biological observations of the insect‘s life cycle. The mysterious disappearance of the Large Blue Butterfly across most of northern Europe was originally put down to its popularity among insect collectors [Telegraph]. Then biologist Jeremy Thomas spent six summers in the 1970s studying the very last colony of large blue butterflies in the United Kingdom, and determined that the butterflies were dependent on one species of red ant for their survival–and those ants were losing their habitat.
The butterflies lay their eggs on flowering thyme plants, and the hatched caterpillars fall to the ground and begin to impersonate immature red ants. They secrete chemicals and even make noises that make the red ants believe they are wayward grubs. The ants then mistakenly carry the caterpillars to their underground homes and keep looking after them even though the adopted intruders gobble ant grubs for 10 months before forming a chrysalis and flying away as adult butterflies [Reuters].
Scientists may finally be on their way to controlling the pesky fire ants that have invaded the American South: They’re releasing swarms of parasitic flies that first turn the ants into zombies and then decapitate them. The non-native ants are at the top of scientists’ hit lists because they cause an estimated $1 billion in damage in Texas each year. The insects swarm on circuit breakers and other electrical equipment, damaging them severely. Swarms of the stinging insects can also severely injure humans and can kill smaller animals, such as calves and pets, that stumble across nests [Los Angeles Times].
Over the past ten years, Texas agricultural researchers have begun releasing several species of phorid flies, imported for this task from the South America. The flies “dive-bomb” the fire ants and lay eggs. The maggot that hatches inside the ant eats away at the brain, and the ant starts exhibiting what some might say is zombie-like behavior…. “There is no brain left in the ant, and the ant just starts wandering aimlessly. This wandering stage goes on for about two weeks” [Fort Worth Star-Telegram], says researcher Rob Plowes. Eventually the ant’s head falls off and the mature fly emerges, ready to lay its own eggs in a new round of ants.
Each adult Argentine ant has two chemical fragrances that send out critical messages to other ants in its colony, in what is literally a matter of life and death. Normal, still-breathing adult workers carry chemicals signaling “Dead ant — haul to burial pile” on their outer covering, proposes [entomologist] Dong-Hwan Choe…. What prevents awkward mistakes about who’s really dead are two additional compounds also found on the covering of living ants, Choe suggests. These compounds temporarily inhibit responses to the death cues by signaling, “Wait — still alive so far,” Choe and his colleagues report [Science News].
Choe’s study, which was published in the Proceedings of the National Academy of Sciences, set out to examine the corpse-ridding behavior, or necrophoresis, that is common to many ants and other social insects, and helps maintain good sanitation in the colony…. The prevailing theory of necrophoresis had been that ants were responding to fatty acids and other chemical cues from the decomposing corpse. But the researchers noticed that ants would haul a corpse away within an hour after death — before much decomposition began [The New York Times].
A species of European butterfly has an excellent trick for protecting itself during a vulnerable stage of life. As the caterpillars prepare to enter their inactive pupal stage they emit ant-like chemicals that cause red ants to scoop them up and bring them inside the ant colony. Then, to get star treatment, the caterpillars make a rhythmic noise that resembles the call of the ant queen. That’s enough to get the worker ants’ undivided attention, a new study shows. “They appeared to be treating the caterpillars as if they were the holiest of holiest, the pinnacle of power, the queen ant” [New Scientist], says lead researcher Jeremy Thomas.
If the colony is attacked, the worker ants save the caterpillar before they save ant larvae, and when food is scarce the ants have been known to kill their own larvae and feed them to the deceitful interlopers. But there’s one ant who is not fooled. Researchers set up an experiment in which a butterfly pupa pretending to be an ant queen was placed in a chamber with worker ants and four real ant queens. The ant queens began to attack and bite the caterpillar, but the workers intervened, biting and stinging their own queens, which they then pulled to a far corner of the chamber while other workers attended the pupa [AP]. Researchers note that this situation would not arise in the wild, where queens and larvae inhabit different chambers, but say it shows where the workers’ loyalty lies.
80beats is DISCOVER's news aggregator, weaving together the choicest tidbits from the best articles on the day's most compelling topics.
80beats is written by Veronique Greenwood and Valerie Ross. This team darts through each day's science news faster than the ruby-throated hummingbird that beats its wings 80 times per second. Send ideas, tips, suggestions, and complaints to [azeeberg at discovermagazine dot com].
Here’s one that I didn’t touch on in DISCOVER’s creepy 
Many children have a “bug period”–a time of life when bugs and creepy crawlies are a source of endless fascination and learning. Naturalist 
In leafcutter ants and honeybees, it’s survival of the fittest sperm. Biologist Boris Baer, for a 
In an ironic twist, the weaponry of the fire 
At some point in the first half of the 20th century, a couple of 
In a rare conservation success, a beautiful butterfly species that was headed for 
Scientists may finally be on their way to controlling the pesky fire 
Each adult Argentine 
A species of European butterfly has an excellent trick for protecting itself during a vulnerable stage of life. As the caterpillars prepare to enter their inactive pupal stage they emit ant-like chemicals that cause red 
