Author Archives: Roberta

There's a question for the Consult-Ant this week. (The “Consult-Ant” started on the Leaping from the Box website, where I answered questions about ants and ant farms. From now on I will post the answers here, and when Karen has time she will also post the answers on her site.)

Question:

This comes from Ol Donyo Orok Hill in Southern Kenya (on the border with Tanzania) at an altitude of around 4500 feet.  I found these ants all dead at the entrance of a hole (what I assumed to be their nest).  This was far enough away from any human habitation, farming, or other activity (other than some goat herding) that I ruled out the use of insecticide.  There were a few more dead, spread out of the the space of about 1 square foot, but the attached photo shows the vast majority of them in a small, dense pile.  Some of their exoskeletons were coming apart (especially the tips of the abdomens), but it didn't look like ruptures from predation, rather just decay.

The stem of the plant in the photo is Solanum incanum (Poison/Sodom Apple), which is both indigenous to the area and poisonous to humans and domestic stock, but I doubt that ants would eat something familiar to them which if it was poisonous.  I don't know what species of ant they are, but the closest I can get is some Pachycondyla sp. (though I'm really not sure).

Do you know what may have caused this seemingly sudden mass die-off?

Answer:

Taking a look at Ants of Africa for ants in the genus Pachychondyla, your identification seems in the right ballpark. Are there any experts out there who can tell us more about what kind of ants these are?

As for what has happened, when I've seen similar piles after a couple of events. Most commonly, either the ant colony had a battle with a neighboring colony or there has been some adverse weather that has caused a mass die off.

If the battle was with a neighboring colony of ants, not all the causalities will be torn apart, particularly if the damage was caused by stings or chemical weapons.

Flooding of portions of the nest during heavy rains can also cause big die offs in species that nest underground.

Readers:  Do you have any suggestions why these ants might have died?

Please leave your thoughts in the comments.

Today we're featuring a new resource for ant enthusiasts, Ants of Florida: Identification and Natural History by Dr. Mark Deyrup. It was published in November 2016.

Why Florida?

With 239 known species of ants, Deyrup makes a good case that Florida is a leader in ant diversity, if not "the 'antiest' state." At Archbold Biological Station alone -- where he works -- researchers have found 128 species. (Of course, it has also been studied more intensively than many other areas).

What's Inside The Book?

Have you ever been frustrated when an identification guide gives no information about what a given species does or disappointed when authors of natural history books assume the reader can already recognize all the species they discuss? Ants of Florida shows how to combine the two successfully.

Starting with a 12-page Overview of the Ants of Florida, the bulk of the book comprises of Species Accounts of every one of the species of ants currently found in Florida. Each account contains:

  • The scientific name of ant
  • Common name of ant
  • Taxonomy information
  • Distribution
  • A Natural History summary
  • Name Derivation

You may wonder why the author included name derivations for every species, but it's always enlightening to learn about them. They reveal information both about the history of the species, and about the people who discovered and named them. I have to ask: does it seem like all entomologists also interested in etymology?

Every ant gets equal treatment, but Dr. Deyrup admits he is partial to ants in the genus Strumigenys.

(Photograph of Strumigenys rogeri from www.Antweb.org under license Creative Commons License)

Back matter includes a Checklist of Florida Ants, Literature Cited, Plates, Distribution Maps, and an incredibly comprehensive Index. With a small font and dense text in over 400 pages, there is a lot packed into this book.

The 90 plates of illustrations are particularly well done with an emphasis on key characteristics used to distinguish similar species. The first two plates show morphological terms applicable to all ants.

Is This Book For You?

Although pricier than a standard hardback novel, in terms of density and value of information this book is a huge bargain.

You will obviously want a copy is you live in Florida or anywhere in the southeastern United States, for that matter. You will probably also want a copy if you ever intend to visit Florida or the southeastern United States. Let's face it, after you see this book, you will want to visit Florida.

What about for the rest of us? Does the book have a broader appeal?  Consider:

  1. A number of the species covered have widespread distributions, such as the Patagonian rover ant, Brachymyrmex patagonicus, the carpenter ant Camponotus pennsylvanicus or the crazy ant, Paretrechina longicornis.
  2. Even for those ants found only in Florida, it may be useful to compare them to similar species found in your region.
  3. By reading it, you can learn a lot about ants in general. For example, Dr. Deyrup points out on page 205 that some genera of ants aren't commonly found in warm humid climates, such as Lasius, Formica, and Myrmica.
  4. It gives a glimpse into the lives of people who collected and named ants in Florida, as well as the scientists who research them.

The bottom line is that Ants of Florida: Identification and Natural History is a comprehensive, well-organized, and informative resource. If you're wild about ants like we are, you'll want to pick up a copy.

Hardcover: 437 pages
Publisher: CRC Press (November 9, 2016)
Language: English
ISBN-10: 1498754678
ISBN-13: 978-1498754675

The Author:

Biodiversity with Dr. Mark Deyrup: Archbold Biological Station, Part One from Archbold Biological Station on Vimeo.

Disclosures: This book was provided by the publisher or 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 not extra cost to you. Any proceeds help defray the costs of hosting and maintaining this website.

2 Comments

Want to learn more about ants?  Sign up for the American Museum of Natural History's Ants of the Southwest class to be held August 9 through 18, 2017 at the Southwestern Research Station in Portal, Arizona.

This class is a golden opportunity because Arizona is a fantastic place to study ants, largely due to the unique and diverse habitats found here. In addition honeypot ants like the one in the photograph, we have more than 350 different species.

What does the course cover? Among other things, students will be given the opportunity to study behavior and communication in ants, learn how to keep ant colonies in the laboratory, make an ant reference collection, and learn some photography techniques.

Cost:  Tuition is $1206 (includes room and board).

If you are interested, you will need to fill out the application form at the course website by July 1, 2017.

Note:  Another ant class, the California Academy of Sciences Ant Course, is not being held this year.

Have you taken this course? Leave us a comment to let us know about your experiences.

2 Comments

When the weather is cold and cloudy, many people dream of sunbathing on a warm, tropical beach. What about ants? Evidence suggests that at least some ants spend time basking in the sun.

See, for example, this video of harvester ants (Pogonomyrmex) sitting in the sun after a rain.

News From Rockcliff Farms blog has photographs of imported fire ants (Solenopsis invicta) sunbathing in large groups during a midwinter warm spell.

Some possible reasons for sunbathing/basking:

  1. Warm up or increase body temperature, particularly in poikilotherms (animals whose internal body temperature varies with the external environmental temperature)
  2. Exposure to ultraviolet light can kill microorganisms, such as bacteria, on the outer surface
  3. Exposure to ultraviolet light in vertebrates induces the production of Vitamin D

 

In his 1995 book Animal Architecture, Juhani Pallasmaa stated wood ants (Formica sp.) use heat captured by basking in the sun to warm their nests.

Kadochová, Frouz, and Roces (2017) recently tested this idea in the laboratory. They found Formica polyctena workers are willing to bask under an artificial heat source, which in this case was an infrared lamp. The authors of the paper didn't find evidence basking workers had a sustained increase in metabolic rate, but did suggest that heat energy absorbed during sun basking can be dissipated enough to increase the temperature inside of the nest. Cool! (yeah, I couldn't resist.)

The authors of the study found certain behavioral castes bask more than others. It would be worth investigating if workers which spend more time with the brood are more likely to bask. The ability to increase the nest temperatures around the brood during cold spells would likely be an advantage.

What do you think?

References:

Kadochová Š, Frouz J, Roces F (2017) Sun Basking in Red Wood Ants Formica polyctena (Hymenoptera, Formicidae): Individual Behaviour and Temperature-Dependent Respiration Rates. PLoS ONE 12(1): e0170570. doi:10.1371/journal.pone.0170570

 

(Amazon Affiliate Link)

Pallasmaa, J. 1995. Animal architecture. Helsinki: Museum of Finnish Architecture. 126 p.