Tag: Army Ants

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Army Ants: Nature’s Ultimate Social Hunters Book

Looking for a last minute gift for an ant aficionado or nature enthusiast?  Army Ants: Nature’s Ultimate Social Hunters* by Daniel J. C. Kronauer is the perfect choice.

(*Amazon Affiliate Link)

Written to be accessible for the general audience, the book features Kronauer’s eye-catching, gorgeous full-color photographs. In fact the illustrations might make you think it could  be a coffee table book, but don’t be fooled. Army Ants is full of serious, sometimes cutting-edge science, too.

What’s in the book

In the prologue, the reader learns about how popular culture has viewed army ants, as well as a quick introduction to the rest of the book. Kronauer explains he will focus on two species, Eciton hamatum  and Eciton burchelli.

Chapter One starts with the recognition of Eciton army ants by early European naturalists and the problems they had naming the species. It is a fascinating bit of scientific history and took some effort to untangle. Eventually, the taxonomy is sorted and science progresses.

In Chapter Two, readers discover how different groups of army ants fit in with other ants in the evolutionary tree, how they are different from one another and how they are similar.

The next chapters cover specialized army ant biology:  mass raiding, nomadic lifestyle, and reproducing via colony fission.

Chapter Three discusses how army ants forage for prey during raids. For example, Eciton hamatum specializes in preying on ants and social wasps, whereas Eciton bruchelli raids ants as well as many other arthropods.  Do Eciton army ants raid the other abundant ants in the area, leafcutters? You will find out. He also mentions butterflies, flies, and birds that follow the raiding columns ( previous post describes antbirds).

Chapter Four delves deeply into the colony life cycles of the different species.  Army ants cycle between a nomadic phase when they move from place to place, and a statary or settled phase when the ants stay in one place for a few weeks. When they are statary, the ants form a living nest with their own bodies called a bivouac. All those ants working together to produce a physical structure that can even regulate the temperature and humidity inside is pretty amazing.

Chapter Five reveals how army ant colonies reproduce via fission, where colonies split up workers into two (or more) groups, one following the established queen and the other with a new, young queen. It is reminiscent of the swarming process in honey bees.

The final chapter, aptly named “The Traveling Circus”, focuses on all the other arthropods that live with, on, and travel with army ants. Mites and beetles are particularly common myrmecophiles. Some of their adaptations to life with army ants are mind blowing. On page 266 check out the mite that attaches to and takes the function of the tarsi of an army ant.

In the back matter is a full glossary, tons of references, and an index.

Discussion

Army Ants is both an entertaining read and a good general reference to this specialized group of ants. Kronauer’s enthusiasm for his subject and expertise shine through on every page. Even someone who knows quite a bit about ants will probably find things that are new.

One unexpected aspect of reading the book the ability to armchair travel to tropical locations at a time when travel currently not an easy option. Although Kronauer doesn’t write about his adventures in great detail, on page 222 he mentions receiving the news that a colony of army ants was getting ready to fission and immediately booking a flight to Costa Rica to observe it. That’s a lifestyle most of us only dream about. By reading the book, we get to travel along with him.

If you are interested in ants or know someone who is, grab a copy of Army Ants today!

Publisher : Harvard University Press (October 6, 2020)
ISBN-10 : 067424155X
ISBN-13 : 978-0674241558

(Featured post image is a public domain photograph of Eciton burchelli by Alex Wild)

Disclosure: This book was provided by the publisher for review purposes. Also, I am an affiliate with Amazon so I can provide you with cover images and links to more information about books and products. As you probably are aware, if you click through the highlighted title link and purchase a product, I will receive a very small commission, at no extra cost to you. Any proceeds help defray the costs of hosting and maintaining this website.

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New species for the blog: Neivamyrmex Raiding Dorymyrmex bicolor

People who go to u-pick vegetable farms usually come home with lettuce or corn or tomatoes. When I went to a u-pick vegetable farm near Phoenix, Arizona, I came home with photographs of ants, instead.

It wasn’t surprising to see numerous circular mounds with a single entrance hole in the center.

The nests are made by a common ant in the low desert, Dorymyrmex bicolor. As I’ve written previously, D. bicolor seems to prefer to nest along dirt paths or roads. The garden had plenty of those.

Here’s another nest, again with an entrance hole in the center, and covered with active ants.

The workers here were pulling out clumps of what looked like dirt. Can you see the single petiole that is characteristic of the species?

After seeing about three dozen or so circular nests like those above, I found this one.

Same rough shape, but notice anything different?

Where are all the ants?

From another view, the entrance hole is actually blocked with dirt.

Finally, I can see some ants, but those aren’t Dorymyrmex bicolor workers.

The workers exiting from this nest are uniform in color. They have a petiole and a postpetiole.  Notice anything else about them?

The Dorymyrmex worker ants from the same perspective have large eyes. See any noticeable eyes from this view?

Having no noticeable eyes is a characteristic of Neivamyrmex army ants (Note:  They do have a single eye facet, but it isn’t obvious.)

The exact species is much more difficult to figure out.

Wayne P. Armstrong found some similar Neivamyrmex near the Superstition Mountains in Arizona, which are close to the farm where I found these ants. Gordon Snelling identified Armstrong’s ants as Neivamyrmex leonardi. The ones I found could be N. leonardi or one of several similar species.

In any case, Neivamyrmex army ants resemble their larger namesakes because they are always on the move. They don’t make permanent or long term nests like the Dorymyrmex, but instead raid nests of other ants stealing the brood for food. Seems like in this case a Dorymyrmex bicolor colony was a target of their raid. Armstrong reports Neivamyrmex workers raid Pheidole nests, as well.

So, I didn’t bring home lettuce, but maybe something even better from the u-pick farm.

Have you ever seen Neivamyrmex army ants?

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New World Army Ants: Horror or Hype?

Are New World army ants the dangerous killers that movies and other media suggest?

After all, look at the jaws (mandibles) on the Eciton burchelli soldier. (Photograph by April Nobile / © AntWeb.org / CC-BY-SA-3.0, downloaded at Wikimedia) Appears fairly fierce.

So, are they really horrors?

When reading the recent review of the Antsbirds & Ovenbirds book, Ossein asked for more information about Skutch’s descriptions of the army ants. Alexander Skutch spent years in the tropical rainforests where he commonly encountered army ants. Did Skutch worry?

On page 21 of the book (link will take you directly to the page), Skutch writes of Ecition burchelli:

“These ants are not nearly as formidable as sensational accounts depict them. They specialize on invertebrate prey. Active vertebrates of all kinds readily avoid them, perhaps not without a few stings.”

He goes on to add that

Often I have continued to sit at my table and write, while army ants scurried over the floor around me and the ceiling above me.”

On page 24, Skutch makes the point that New World army ants don’t even eat dead vertebrates. He recalls a time when a dead bird fell in the path of the raiding army ants and another time a dead snake was left in the path of the ants. Both times the army ants did not consume the remains, even though they were actively foraging.

The antbirds that follow the army ants are in no danger. In this video, you can see an elusive bare-eyed antbird standing while ants run nearby. It seems more concerned about the camera than the ants.

Bottom line, when it comes to New World army ants, the fervor has been mostly hype.

Have you ever heard that villages in some areas welcome army ants into their homes for pest control? Does anyone have a primary source for to back this up?