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In the aftermath of Hurricane Harvey, we are all worried about the residents of Houston and the Galveston Gulf Coast. Hurricanes and flooding are a deadly serious matter and my heart goes out to everyone dealing with loss or damage caused by the disaster. As Houston residents and first responders worked together to survive and mitigate the floodwaters with boats, pumps, sandbags, and evacuations, they were treated to the (horrible) spectacle of a very different group of social animals responding to the crisis with a different group strategy.
Red fire ants (Solenopsis invicta) are a tough species of stinging fire ants from South America. Like humankind they are invasive generalists which can survive anything and have quickly spread worldwide because of their hardy resilience and various ingenious group strategies. I have been meaning to blog about them because they are a sort of alien red mirror of humanity (and I have been trying to get back to writing about superorganisms and the question of what constitutes an organism anyway). Because of the hurricane, the fire ants have injected themselves into the news cycle, so I am going to mention their flood strategy now and we can return to write about their other interesting behaviors.
Fire ant bodies are waxy and light. They float! But they would all be drowned or swept apart in a serious flooding event (and a single ant separated from the group is effectively dead). Thus when the fire ants sense rising waters they group together in a ball and tightly cling to each other. These living rafts of clamped together ants can float for many days.
If you are in a flooded area and a ball of furious stinging ants floats by you, entomologists and fire ant experts recommend that you not molest it. Like Voltron, the ants can break apart into autonomous fighting units before reforming. Ants do not breathe like people and they drown sort of gradually. We will leave the ants alone and concentrate on human group strategies for getting through crises.
The first known farmers were apparently…ants. Leafcutter ants have been growing fungus on chopped up leaves for at least 50 million years. It is an amazingly long time. Yet, when one thinks of the astonishing range of different “breeds” of animals and crops which humankind has created through artificial selection during the 10 millenia or so years since we started farming, the ants seem a bit lackluster. For all of their workaholic zeal, ants are not as relentless as us in selecting for traits in their crops.
Yet, as we learn more about the ants and their empire, the amazing extent of their symbiosis with the plants they use is beginning to become more apparent to us. Because of the vastly greater timeline of their endeavors, they have coevolved in astonishing ways. An example of this can be found in the homes of Philidris nagasau, a species of leaf cutterant native to Fiji. These ants literally grow their homes out of Squamellaria, an epiphytic plant which grows on tropical trees.
The Economist described the mechanism through which the ants grow a home (or, alternately, the way the epiphytic plant obtains an army of insect servants):
P. nagasau worker ants harvest seeds from their epiphytic homes, carry them away, and then insert them into cracks in the bark of suitable trees. That done, they patrol the sites of the plantings to keep away herbivores, and also fertilise the seedlings as they grow by defecating into hollow structures called domatia that develop in the bases of the plants’ stems. As a Squamellaria grows, its domatium swells (see picture) and develops galleries that can accommodate ants—which then move in. This, and the plant’s habit of growing flowers that generate nectar long after they have been pollinated, provide the evolutionary quid pro quo that makes the relationship between insect and epiphyte work.
It is incredible that the ants grow their own houses. Yet, as one looks more closely at familiar domestic arrangements with this story in mind, they start to seem less familiar. Is farming really as unique as we make it out to be, or does it resemble mutualistic arrangements found throughout the natural world.
We would never say we co-evolved with goats, cows, and horses: their domestication seems like a one way exchange to us. Yet an outside observer might look at our leather sofas, cheeseburgers, cavalry charges, or angora sweaters and come to a different conclusion.
Strange Ocean World (Wayne Ferrebee, 2015, colored pencil on paper)
Well…it was another day that got away. What with work and dinner and the grind, I failed to write about beaked whales. Don’t worry: those magnificent diving experts cannot escape our pen forever, but, in the interim, we must fall back on my daily doodle book (which Ferrebeekeeper cognoscenti know is a little moleskine sketch book that I carry around and draw in during my spare time). I have a big sarcophagus-shaped pencil tin too—which is full of colored pencils and markers to bring my drawings to life. The first sketch however (above) only required one “Blue Denim” colored pencil. It’s a little unclear, but I think it is a picture of the future oceans filled with bathyspheres, synthetic ocean life (to replace the fish we are recklessly killing off), and ships driven by fanciful propulsion. Synthetic beings and post-humans fly through the weird clouds of this strange ocean world. In fact, maybe it’s not Earth at all, but somewhere else entirely—an ocean world of oddly familiar alien marvels.
City with Glowing Crystal (Wayne Ferrebee, 2015, ink on paper)
Next is another troubling pastiche of nature and technology. A happy monster ambles by a shambling city while a gambling demon tosses dice at a magic crystal. Reptiles and weeds fill up the foreground as strange elongated opossums creep in from the sides. It’s just like now! This might as well be a CNN photo about the 2016 election. This image may need to be colored in. What do you think?
Succulent Fruit (Wayne Ferrebee, 2015, Colored Pencil and Ink on paper)
Finally, thanks to enthusiastic comments from my favorite readers, I included more fruit. One of my tasks at my new day job is overseeing the fruit supplies for a big office full of desk jockeys who spend all day looking at important documents. Because of ancient precedent, almost all of the fruit is bananas, and my colleagues beg piteously for different fruit. I have provided their wants…in this fantasy drawing which shows a succulent world of juices, seeds, and glowing tutti-fruit color. It could also be that there is a statement here about our world of agriculture, selective breeding, transgenic alteration, and over-consumption…or possibly it is just a fun doodle I made at lunchtime. As always, thanks for looking at my little artworks. I treasure everybody’s comments (though I realize I have been slower than usual to respond). Let’s keep enjoying the rest of summer. I’ll keep drawing (and the post about beaked whales will appear soon). Cheers!
Ant (M.C. Escher, 1943, Lithograph)
Here are two beautiful prints of ants by the great Dutch artist M.C. Escher. In art, ants are frequently metaphors for over ripeness, rottenness or ruin (think of Dali’s ants). Yet in Escher’s works they are something else entirely. The first print, a lithograph from the grim year 1943, shows a single ant. An ant alone hardly seems to exit—they are pieces of a larger superorganism. Yet here we have one of the creatures all by herself. How lovely and delicate she is: look at her crimped antennae and graceful segmented legs. Yet the ant’s head is down, and she has a slightly forlorn cast—as though she is about to be crushed. The print was made at a time when the nations of the world organized themselves into vast battling hives and individual humans hardly seemed to exist any more than individual ants. Working in the occupied Netherlands, the comparison could hardly have escaped the artist.
Möbius Strip II (M.C. Escher, 1963, Woodcut)
The second print is a woodcut from 1963. A line of red ants march stolidly along a Möbius strip. Because the strip they are on is non-orientable, their little universe has only one endless side. The insects are literally traveling forever. Is this print a tableau of futility or a metaphor for the infinite? The question is about more than just the microcosm the ants are trapped within.
Like bee hives, ant colonies have all sorts of specialized ants. Soldier ants with mighty mandibles guard the hive. The queen ant becomes a gargantuan reproductive machine and pumps out an endless swarm of underlings. Drone ants develop wings to fly high into the air to mate with fledgling queens. Yet the strangest of all ant jobs (to my mind at least) is held by honeypot ants.
Honeypot ant repletes (Camponotus inflatus) hanging from the roof a hive tunnel
Honeypot ants are found in six or seven genera of seasonal ants located in Africa, Australia, Melanesia, and North America. The ants function as living granaries/reservoirs. They find an underground location deep in the hive and use their own bodies as storehouses to protect the hive from drought and famine. As soon as they develop from larvae, the specialized honeypot ants transform into grapelike spheroids capable of ballooning to many time the size of normal ants. During the rainy season, when food is plentiful, worker ants stuff the honeypot ants to the edge of bursting with prey and provender. These living warehouses can store liquids, body fat, and water for long periods in their grotesquely distended abdomens. When the dry season hits and resources become scarce, worker ants stroke the antennae of the honeypot ants and the latter to disgorge their precious stores of liquids and nutrients.
image credit: lonelyplanetimages.com
Living deep underground, honeypot ants are seldom seen by people. They were first documented in 1881 by Henry Christopher McCook (a civil war chaplain, polymath, and entomological pioneer). Yet hunter gatherers have known of them since time immemorial. The strange grapelike ants are regarded as a unique delicacy to Australia’s indigenous people who have worked the strange bulbous ants into stories of the dreamtime—the ancient magical creation of the world. Of course the world is not finished and the dreamtime is still ongoing and honeypot ants are out there, engorged in the darkness, doing their part. We just never see them.
In the Iliad, the great Greek epic of ferocity, loyalty, and war, the Myrmidons were the most ferocious and loyal of all of the various Achaean warriors. The myth of how the Myrmidons came into existence reveals the source of their bravery, strength, and discipline as infantry troops. The story combines literature, invaders (for the Myrmidons were ever attacking), and…hymenopterans.
Creation of the Myrmidons (artist unknown)
As with so many other Greek myths, the story starts with the philandering of Zeus, who fell in love with Aegina, who was the eponymous nymph/goddess of Aegina—an island which is located in the Saronic gulf between Attica and Argolis. According to the writer Hesiod (and later Ovid) Zeus appeared to the nymph as an eagle and loved her. From their union came the demi-god, Aeacus, born as king over the island. Hera, jealous as ever, punished the inhabitants of the island for Zeus’ affairs by sending a plague (or possibly a dragon) to destroy them all except for the immortal Aeacus. Devastated by the deaths of his subjects, the lonely Aecus prayed to Zeus to repopulate the island. The king of the gods heard the prayer and responded by transforming a colony of ants in an oak tree into men and women. These new people were tough, warlike, and hive-minded—just like the ants they originated from. Aeacus eventually wearied of kingship and turned the throne over to his son Peleus (one of the heroes of the ill-fated Caledonian boar hunt) who eventually wed the sea-nymph Thetis.
The creation of the Myrmidons
There is another (possibly older) myth which is more troubling. In this alternate story, Zeus transformed himself into an ant in order to seduce Eurymedusa, the daughter of a river god. She bore a son, Myrmidon, and the antlike Myrmidons all descended from him. I think I prefer Ovid & Hesiod’s version of the story!
Myrmidons (Tristan Schane, oil on illustration board)
Of course, in accordance with the universal law of disparity between intention and result, the Myrmidons (who enjoyed war more than the other Greek armies) ended up sitting out most of the battles mentioned in the Iliad due to the feud between Achilles and Agamemnon—but their ferocity was well-documented in Greek letters. A passage from the end of the Iliad describes how excited the Myrmidons became when Achilles finally freed them to join the battle after holding them back while other men fought:
Meanwhile Achilles made his round of the huts and called all the Myrmidons to arms. They gathered like a pack of ravening wolves filled with indescribable fury, like mountain wolves that have brought down a stag with full antlers, and rend it with blood-stained jaws then go in a mass to drink, lapping the dark water with slender tongues, dripping blood and gore, the hearts in their chests beating strong and their bellies gorged. (Iliad, Book XVI, translated by A. S. Kline)
The popularity of the Iliad has meant that the Myrmidons were not forgotten: the word has become part of the English lexicon where it means a completely devoted warrior-minion.
Crazy Ant (Nylanderia fulva)
Our nation is being invaded! The intruders number in the millions. They are wiping out entire ecosystems, destroying electronics, and setting fires. Fortunately the invading species, Nylanderia fulva, is rather small: each individual measures only 3.2 mm (.12 inches). In 2002 the ants arrived on America’s Gulf Coast from Argentina or Brazil where they live naturally. These ants are called Nylanderia fulva because of their brownish yellow fulvous color, but in America they are more commonly known as crazy ants (thanks to their erratic and non-linear walking patterns) or Rasberry ants—in honor of Tom Rasberry a Texas exterminator who discovered them in Texas.
The crazy ants have spread extensively in Texas and Florida and they have footholds in Mississippi and Louisiana. They are highly successful foragers and hunters of small arthropods and, like some other ants, they farm aphids (!). Nylanderia fulva is capable of forming extremely large hives with multiple queens—which gives them surprising immunity from many common American insecticides and ant-killing chemicals. They are out-competing native fire ants and changing the micro-fauna of the areas where they are flourishing.
For whatever reason, crazy ants are attracted to electronics. Because of their small size, they climb inside all sorts of switches, circuit boxes, and electric gizmos. If an ant stumbles into a transistor and dies, its corpse emits a chemical which causes fellow hive members to rush to the scene (this is an evolutionary strategy for fending off attackers). Unfortunately, the reinforcement ants are themselves electrocuted which causes a grim feedback scenario. These ant death spirals can cause electronics to become disabled, or switch permanently on/off, or just catch fire (since they are jam packed with electrified ant corpses).
Southern Tamandua (Tamandua tetradactyla) with baby
Tamandua is a genus of arborial anteaters with two species, the southern tamandua (Tamandua tetradactyla) and the northern tamandua (Tamandua mexicana). Tamanduas have prehensile tails which help them grip the trees, bushes, and scrub where they hunt for ants, termites, and bees (which they vacuum up through a tubular mouth or capture with a 40 cm long sticky tongue). The two species inhabit a large swath of the Americas—the northern tamandua ranges from Mexico down through Central America and west of the Andes through coastal Venezuela, Columbia, and Peru. The southern tamandua inhabits the entire area surrounding the Amazon basin and ranges from Trinidad, through Venezuela, the entirety of Brazil, and into northern Argentina. Tamanduas weigh up to 7 kilograms (15 pounds) and grow to lengths of about a meter (3 feet).
Northern Tamandua Anteaters (Tamandua mexicana) by Sara L Zering)
Tamanduas have immensely powerful arms which they use for climbing and ripping apart ant and termite colonies. If threatened they hiss and release an unpleasant scent (they can also grapple by means of their formidable arms and huge claws). The creatures spend much of their time in trees and they nest in hollow trees or abandoned burrows of other animals. Tamanduas can live up to nine years. They are widespread but comparatively scarce.
Tamandua hug
Maculinea arion
Hey, look at that! It’s a delicate pale blue butterfly (Maculinea arion) from Europe and northern Asia. What could this ethereal creature have to do with the horror theme which this blog has been following as a lead-up to Halloween? In fact, what does the butterfly have to do with any of Ferrebeekeeper’s regular themes? Butterflies are lepidopterans rather than the hymenoptera we favor here.
As it turns out—the butterfly has a lot to do with hymenopterans. Maculinea arion, or “the large blue butterfly ” to use its not-very-creative English name, may look innocent as a butterfly, but in its larval stage the creature is both appalling and remarkable. Alcon caterpillars are myrmecophiles—which means the caterpillars live in association with ants. Despite the Greek meaning of ”myrmecophile” (to love ants) the relationship is anything but loving on the part of the Alcon caterpillar–unless love is meant in the same way as “to love ham”.
Maculinea arion (Large Blue) larva carried by ant (Drawing by Frohawk)
M. arion caterpillars are relentless predators of ant larvae. The way they obtain this fragile foodstuff is remarkable for sophistication and ruthless guile. When a caterpillar hatches, it lives for a few days on wild thyme or marjoram plants. The caterpillar then secretes a sweet substance which attracts red ants which carry the larva back to their tunnels.
Inside the ant hive, the caterpillar produces pheromones and chemical scents which mimic those of the ant queen. It also scrapes a small ridge on its first segment to produce the same noise as the ant queen. The ants are deceived by the caterpillar’s mimicry and they take it to the chamber where they rear their own larvae. The ants wait on the caterpillar as though it were the hive monarch and they even feed it ant larvae—their own undeveloped siblings. Once it pupates, the butterfly scrapes the inside of its chrysalis to continue the deception. When the butterfly emerges from its cocoon the hapless ants carry it outside and guard it as its wings harden—whereupon the butterfly departs to mate and lay eggs on wild thyme or marjoram plants.
Phengaris alcon
The Maculinea Arion is not the only caterpillar to make use of this strategy. The Phengaris alcon butterfly acts in almost exactly the same way. Here is where the story becomes impressively crazy. A parasitoid wasp, Ichneumon eumerus, feeds on the alcon caterpillar inside the ant hive. The wasp infiltrates the hive by spraying a pheromone which causes the ants to attack each other. While they are busy fighting, the wasp lays its eggs inside the caterpillar. The wasp larvae hatch into the body of the caterpillar (which the ants think of as a queen) and they eat the caterpillar host safe in the cloak of this deception.
The parasitic wasp Ichneumon eumerus. (Image: J.Thomas/Natural Visions)
If an ant hive becomes too saturated with caterpillars it will die and all three species inside the hive will likewise perish). The red ants in this scenario are constantly evolving new pheromone signals to outcompete the caterpillars and wasps—which in turn coevolve with the ants. It’s strange to imagine the troubling world of deception, chemical warfare, and carnage just beneath the ground.
Agriculture is almost unknown in the natural world. Human beings are the only vertebrates known to grow crops or keep livestock (with the possible exception of damselfish which carefully tend little algae gardens). And yet we were not the first animals to invent the concept. Ants have farmed fungi within their tunnels for tens of millions of years. Ants also keep aphids in captivity in order to “milk” them of sugary secretions–or to eat them outright. It is possible that beetles, termite, or snails came up with the concept first, but most evidence points to ants as the first farmers.
An Ant Milking Aphids
Ants do not have a shabby operation either. Leaf cutter ants form the largest and most complicated animal societies known on Earth (other than our own) and a single colony can have over 8 million individuals. Leaf cutters are an ideal example of how adept ants are at farming fungi. Four different castes of worker ants work together to bring back leaf fragments and integrate them into huge fungal gardens. Different species of leafcutters cultivate different fungi from the Lepiotaceae family. Certain bacteria with antifungicidal and antibacterial properties grow within the metapleural glands of the ants. The worker ants use these bacteria to “prune and weed” dangerous or unproductive organisms out of their gardens. Older (more expendable) worker ants carry waste products from the hive to a waste pile where they stir the hive wastes together to aid in decomposition. The waste-management job brings the danger of fungal or bacterial contamination and contaminated ants are exiled to certain death in order to keep the gardens safe. Additionally dead ants from within the hive are carefully placed around the waste pile so as to protect the hive from their decomposition.
Leaf Cutter Ants at the Cameron Currie Lab arrange cut-up leaves into their fungal garden.
According to geneticists who study the rates of mutation within the various fungal cultivars, ants began their farm relationship with fungi around 50 million years ago in the warm Eocene epoch (an era which saw many of the critical relationships in modern ecosystems begin).
Digital Cut-away of an underground leaf-cutter nest
Scientists are also beginning to understand the means by which ants herd their little flocks of aphids. The aphids are smaller insects which feed on the saps and juices of plants (which they suck out by means of specialized mouthparts called stylets). The ants prevent the aphids by flying away by tearing off their wings. The feet of the ants produce chemicals which tranquilize and subdue the aphids and keep them from escaping the “pastures” near the ant colonies. It is believed that aphids also derive certain benefits from this arrangement since the aggressive ants protect them from many of their natural predators.
An Ant with a “herd” of Aphids
For years naysayers belittled the farming achievements of ants suggesting they were little more than symbiotic arrangements. However as entomologists study the ants more carefully they increasingly discover just how complicated and sophisticated those relationships are (involving as they do numerous symbiotic relationships with bacteria in order to produce the chemicals necessary for agricultural control). Additionally, what are humankind’s relationships with our crops and animals if not huge harrowing examples of symbiosis?
