Empire of Ants
The Hidden Worlds and Extraordinary Lives of Earth’s
By Susanne Foitzik and Olaf Fritsche
Ants are amazing insects in my humble opinion and they are a gardener’s friend. They are, like worms, great for the soil. In saying that, there is more to an ant, as tiny as they are, they have been around for centuries. There is more to the ant than meets the eye… Find out more in this excerpt I have kindly been provided with by – RandomThingsTours and publisher Octopus Books for the blog tour.
Taken from Empire of Ants: The Hidden Worlds and Extraordinary Lives of Earth’s Tiny Conquerors by Susanne Foitzik and Olaf Fritsche.
If there’s anyone for whom the phrase L’état, c’est moi (“I am the state”) is true, it’s the ant queen. She is the past, present, and future of her colony. She establishes the colony, bears all the ant workers, males, and young queens that live within it, and once she dies, the colony will often perish soon afterward. And to achieve all this, all she has to do is take a trip out her front door.
A QUEEN’S GIRLHOOD
Ant queens are generally made, not born. Excluding a few exceptions, genes rarely play a part in this process. The nannies in the nest nursery follow to a T the recipe for creating “young queens” (as we call them). First, the red wood ants, Formica obscuripes for instance, take one of the winter eggs, laid at the end of the dormancy period necessitated by the cold temperatures. This process is not possible with eggs laid in the summer, for reasons that remain a mystery to science, and don’t seem to bother the ants much either. But the right egg is just the beginning; the wet-nurse ants must also feed the royal larvae a special diet. This must be plentiful and of high quality. If a red wood ant princess receives this cocktail of nutrients within the first three days of her life as a larva, then the die is cast and she is on the path to becoming a hopeful young queen. And she will be queen—along with a couple hundred of her sisters from the noblest caste.
When it comes to the line of succession, ants do not like to put all their eggs in one basket. The risks of something going wrong are many. From the disappointment of no suitable prince being available or a failure to mate, or the lack of an appropriate location for a new nest nearby, to a deadly encounter with a predator such as a woodpecker—which feast on well-fed young queens—there are any number of opportunities for failure and an early demise. According to estimates, only one in 10,000 young queens is successful in founding a new colony.
The young virgin queens have no inkling of this at first. They are far larger than their worker sisters and have no need to work away, boasting two pairs of wings on their backs. What these are good for, however, does not become apparent until a mild day between June and July in North America,
when it is warm enough.
When the moment comes, the whole anthill is seized by a curious unrest, unlike anything seen in the nest. An innate urge forces the flying young queens and males—still around, for once—toward the nest’s exits. Anyone else wanting to follow the call is held back by scrappy ant workers. Only on a secret signal do all the nests of a particular species open their doors to release the reproductive insects all at once, and in one fell swoop the exits are swarming with flying males and young queens. They traipse around somewhat aimlessly and eventually take to the air for their nuptial flights.
The timing of the nuptial flight during the summer depends on the species of ant. Ants of the species Temnothorax nylanderi fly out in the two hours before sundown, while reproductive ants of the species Temnothorax unifasciatus prefer to swarm in the morning, around dawn. These different swarming times ensure that nuptial flights do not result in hybrid couplings between males and young queens of different species. Some ants don’t leave the nest at all: Young army ant queens stay home on their wedding night, awaiting their lovers in the safety of the nest.
The choreography of nuptial flights also varies according to species. Some males move around in thick swarms of young bachelors, appearing like dark clouds from a distance. If a young queen collides with one of these groups, it swiftly descends into an enormous orgy in full flight. Other queens prefer solid ground. They seek out a romantic spot and emit pheromones, scent signals that no male can resist. Young queens can have sex with as few as one or as many as a dozen males—but just this once. Once the wedding day is over, that’s it for life.
This is why the queen diligently gathers as many sperm as she can and stores them inside a special pouch known as the spermatheca. This can hold a few hundred million sperm cells. Not all that many, when we consider that many queens will produce up to 150 million offspring in the next ten, twenty, or thirty years of their lives. A third to a half of these sperms will fertilize an egg and thus contribute to the next generation of ants. This is a considerably better ratio than human sperm enjoy, as only around one in every 250 million human sperm cells succeeds in merging with an egg. Human sperm also have an expiration date of around a month after production, while the cells stored in an ant queen’s spermatheca remain viable for decades.
Once the sun begins to sink toward the horizon, the wedding celebrations are over. These millions of future mothers and fathers have little to say to each other after sex—and very different fates await them.
About The Authors
Susanne Foitzik is an evolutionary biologist, behavioral scientist and international
authority on ants. After completing her PhD in ant evolution and behavior and conducting
postdoctoral work in the US, she became a professor at Ludwig Maximilian University of
Munich. Currently, she teaches at Johannes Gutenberg University in Mainz, Germany,
where she studies the behaviors of slaveholding ants and different work roles in insect
colonies. Her findings have been published in over 100 scientific papers to date.
Olaf Fritsche is a science journalist and biophysicist with a PhD in biology. He was
previously an editor at the German-language edition of Scientific American, is the author
and coauthor of many books, and has been published in a wide variety of newspapers and magazines.