Ant Research

The human gut microbiome, what microorganisms might be found in our digestive systems and what roles those microorganisms have, has been in the news lately (see the National Microbiome Initiative). The human studies build on research on other organisms such as cows and termites, which have long been known to have archaea, bacteria, and protozoa in their digestive tracts to aid in the digestion of cellulose. What about our favorite creatures, ants? Do they have any gut microsymbionts?

Cepalotes-clypeatus-turtle_ant-Alex-Wild-public-domain(Public domain photograph of Cepalotes clypeatus turtle ants by Alex Wild)

It turns out quite a few species of ants do have endosymbiotic microorganisms in their guts. Studies in the last two decades have shown that ants in the genera Tetraponera, Acromyrmex, Atta, Dolichoderus, Camponotus, Colobopsis, Polyrachis, Echinopla, CephalotesCataulacus, and the ponerine ants Dinoponera lucida, Neoponera curvinodis, Pachycondyla striata, Odontomachus brunneus and Odontomachus bauri have specific bacteria associated with their digestive systems. It is likely more examples will be found as we continue to investigate other genera.

In some cases the ants also have specialized structures associated with the bacteria. For example, some species of Tetraponera have a pouch off the midgut where symbiotic bacteria are housed. Lanan et al. propose the proventriculus (located between the crop and midgut) in some species of Cepahlotes turtle ants acts as a filter to help conserve gut microsymbionts by preventing contamination by other bacteria entering with food. Camponotus ants (and their close relatives) have bacteriocytes, which are cells that house endosymbiotic bacteria of the genus Blochmannia.

Why do ants have gut microsymbionts? As with other animals, the microsymbionts help provide nutrients not accessible by standard digestion, such as vitamins, amino acids, or sterols. Apparently, adult worker ants of many species obtain most of their nutrition from plant fluids, such as directly from nectaries or indirectly from honeydew of insects feeding on plants. Plant fluids are low in amino acids (nitrogen), so the microsymbionts help generate nitrogen sources in exchange for food and a protected environment (Russell, et al.) In fact, Davidson et al. have suggested the presence of gut microsymbionts is what has allowed ants to become so abundant in tropical rainforests.

Seems we have much to learn about how microorganisms are involved in ant digestion and nutrition.

References (links go to journals, most with free .pdf available)

Termite gut microbes

Billen, J., Buschinger, A. (2000). Morphology and ultrastructure of a specialized bacterial pouch in the digestive tract of Tetraponera ants (Formicidae, Pseudomyrmecinae). Arthropod Structure & Development 29: 259-266

Tássio Brito de Oliveira, Milene Ferro, Maurício Bacci, Danival José de Souza, Renato Fontana, Jacques Hubert Charles Delabie, Aline Silva. (2016). Bacterial Communities in the Midgut of Ponerine Ants (Hymenoptera: Formicidae: Ponerinae). Sociobiology Vol 63, No 1 pp. 637-644

Diane W. Davidson, Steven C. Cook, Roy R. Snelling, Tock H. Chua. (2003). Explaining the Abundance of Ants in Lowland Tropical Rainforest Canopies. Science09 May: 969-972

Michele Caroline Lanan, Pedro Augusto Pos Rodrigues, Al Agellon, Patricia Jansma, and Diana Esther Wheeler. (2016) A bacterial filter protects and structures the gut microbiome of an insect
. The ISME Journal advance online publication 12 February: 1-11. doi: 10.1038/ismej.2015.264

Russell, J.A., Moreau, C.S., Goldman-Huertas, B., Fujiwara, M., Lohman, D.J., Pierce, N.E. (2009) Bacterial gut symbionts are tightly linked with the evolution of herbivory in ants. Proc Natl Acad Sci USA 106:21236–21241. doi: 10.1073/pnas.0907926106

Souza, D.J., Bézier, A., Depoix, D., Drezen, M., Lenoir, A. (2009). Blochmannia endosymbionts improve colony growth and immune defence in the ant Camponotus fellah. BMC Microbiol 9:1-8. doi:10.1186/1471-2180-9-29

Ever heard about an ant species and wondered about its distribution? There's an awesome new website that can put the world of ants at your finger tips:  Antmaps.org.

This fully interactive resource shows where to find some 15,000 different species and subspecies of ants. The cover map shows species richness or number of ant species found in a given region. Color coding of retrieved maps reveals whether the ants are native, introduced, or survive indoors, as well.

Example:

Say you want to find the distribution of the army ant, Eciton burchelli.

army_ants-eciton-burchelli-Alex-Wild(Public domain photograph of Eciton burchelli by Alex Wild)

With a few simple clicks and scroll down menus, you can soon see:

Screen Shot 2015-08-14 at 9.40.45 AM(Screen shot of antmaps.org results, used for review purposes)

 According to the map, Eciton burchelli is found in Central and South America. The green areas indicate the areas where the army ants are native.

Sometimes these types of websites are revealed too soon and are clunky to use, but that is not the case here. The map creation process seems to have all the "bugs" worked out, so to speak. Antmaps turns out to be a quick way to get an idea of where to find a particular species of ant without searching through hundreds of references by hand. The authors do concede that the database is a work in progress and ask that myrmecologists help verify the records by reporting errors.

Antmaps.org is a joint venture between the University of Hong Kong and the Okinawa Institute of Sciences and Technology, led by Dr. Benoit Guenard and Evan Economo, in collaboration with Michael Weiser, Kiko Gomez, and Nitish Narula, among others. It is part of the The Global Ant Biodiversity Informatics (GABI) project.

 Have you used Antmaps yet? What did you think of it?

 

Want to learn more about ants? Have some time and money you can spend this summer? Then think about taking Ant Course 2015!

The Ant Course is going to be held August 6-16, 2015  at the Southwestern Research Station in Portal, Arizona.

southeastern-AZ

 

In case you were wondering, Portal is in southeastern Arizona on the east side of the gorgeous Chiricahua Mountains. Although it may seem like a hot, barren desert, Arizona is actually a fantastic place to study ants, with some 350+ species found here. We have honeypots, harvesters, leafcutters, and army ants, as well as bigheaded ants. etc.

Sponsored by California Academy of Sciences and Museum of Comparative Zoology (with funding from National Science Foundation), the Ant Course is intended to help individuals learn about ant field collection techniques and identification (they promise to genus).

To get you in the mood, here's what happened when the course was offered in Arizona in 2011:


(Scary, isn't it?)

Although the course is open to everyone, enrollment is limited to 30 people and priority will be given to students doing research. Check the Ant Course website for details and costs, as well as links to the application.

Deadline for applications:  April 1, 2015

This just might be my year to give it a try. What about you?