Tag Archives: Fort Worth

The Spatial Ecology of the Comanche Harvester Ant

I have successfully presented my dissertation work and am currently finishing up the revisions for the final submission to the University of Texas at Arlington for the PhD degree. I expect the final dissertation to be available from the university library by July 2015.

The title of the dissertation is: The Spatial Ecology of the Comanche Harvester Ant, Pogonomyrmex comanche (Hymenoptera, Formicidae)

Dr. Esther Betran was the chair of my committee (UTA).

Other committee members were:

Dr. Jonathan Campbell (UTA)

Dr. Paul Chippindale (UTA)

Dr. Sophia Passy (UTA)

and Dr. Walter Tschinkel (FSU)

Here is the slide presentation and the notes which are numbered to correspond to the slides. I have included some of the corrections that came out of the discussion with my committee and otherwise have noted where there are other problems which I am addressing in the revision.

The slides:

and the notes:

Prairies in a Changing World: State of the Prairie Conference 2014

Conferene poster

The Native Prairies Association of Texas (and the Coastal Prairie Partnership) had their annual meeting in Fort Worth at the Fort Worth Botanical Garden from May 29 – May 31, 2014.  I was invited to present my research on ants in the prairies of the Fort Worth Nature Center in Fort Worth and the Southwest Nature Preserve in Arlington, Texas.

I also attended most of the meeting and gained a lot from the presentations I attended and especially from hobnobbing with other attendees.

**I want to pass on that Native American Seed is producing a seed mix especially to attract native bees which will be available this fall. Here’s the link to this Seed Source.

Here is the agenda for May 30 and May 31, following which I post my notes on the few talks I was able to attend with some comments and finally my presentation and extensive notes on the slides.

May 30 Agenda

State of the Prairie Agenda for May 30

May 31 Agenda

State of the Prairie Agenda for May 31

My Notes and Comments

State of the Prairie Conference Notes

Demonstration Prairie 5

The Demonstration Prairie at the Fort Worth Nature Center (photo above)

I presented my research on the ant species I have found in 17 sites at the Fort Worth Nature Center and what this means for 1) the possibility of using ants as bioindicators and 2) for the ecology of the Cross Timbers Ecoregion.

“Jills of All Trades: Ant Diversity and Flexibility in the Cross Timbers Ecoregion”

Here are my notes. In these notes I include quite a bit more than I was able to cover, in part, so that if you did not attend, you can follow the slides. If you have questions, message me.

Jills of all Trades_Presentation Notes

And finally, I mention a 10 minute digital recording I made of the Comanche harvester ant “remodeling” a ground bee nest that was too close to the ant nest. Here is a the video:

Ants on Baits at the Fort Worth Nature Center

This is the demonstration prairie located in front of the Hardwicke Interpretative Center of the Fort Worth Nature Center in Fort Worth, Texas. The students set up some bait stations in this area.

This is the demonstration prairie located in front of the Hardwicke Interpretative Center of the Fort Worth Nature Center in Fort Worth, Texas. The students set up some bait stations in this area.

On April 29, 2014, sixth graders from Trinity Valley School (Ms. Julie Frey) in Fort Worth, Texas came to the Fort Worth Nature Center to learn about horned lizards and the ants they eat, mostly Pogonomyrmex ants, commonly called harvester ants because they mostly eat seeds. As part of their time with me, we set up tuna and pecan sandies cookie baits and made observations. At the conclusion, the students collected the ants for identification. I also recorded some video of the ants.

Although we attempted to set this up as a controlled study, it was a good preliminary investigation. The students explored their areas — limestone ridge, woods, or open prairie — and tried alternative ways of placing and using the baits. They did a good job of investigating.

I set them up with a data sheet to record location, weather, type of bait (tuna, cookie, or both), time of first arrival to the bait (and what this was), time for first ant arrival, observations (numbers of ants; rate of foraging, interactions, etc.), and how many ants on the baits after 5 minutes. (I did not get the data sheets so I cannot share that part.)

I recommend this kind of exercise for teaching about science method, forming hypotheses, investigating insects and foraging. It is easy to do and can be done anywhere. You can develop all kinds of ideas and possible experiments from this kind of work — myrmecologists do so all the time.

Here is a summary of the ants the students collected and some short clips from the video.

METHODS for Identification:

The students collected the ants from the baits and put the ants and bait into jars. In the Formanowicz lab at the University of Texas-Arlington, I separated the ants from the baits, rinsed them and placed them in 95% ethanol. They were identified to species using various on-line and published identification keys.

The lab bench: using a Nikon dissecting microscope with 40X magnification.

Lab bench for ant identification

Lab bench for ant identification

Sorting the ants from the baits

Sorting ants collected on tuna bait

Sorting ants collected on tuna bait

Some photos of the ants: Photos were taken using a dissecting microscope at 40X with a cell phone.

Camponotus americanus: This is a carpenter ant that nests in wood and is mostly found in woodland though they may wander into prairie. These ants are large, 1.5 cm.

Camponotus americanus collected from baits at the Fort Worth Nature Center.

Camponotus americanus collected from baits at the Fort Worth Nature Center.

Crematogaster sp.: Crematogaster is called an acrobatic ant because their gaster (part of the abdomen) is attached such that the ants can carry it above their heads — in a rather acrobatic posture.

Crematogaster

Dorymyrmex flavus: Ants in the genus Dorymyrmex are easily recognized by a cone shaped structure on the their dorsal surface (just before the gaster). Their common name is cone or pyramid ants. The cones differ in size and shape. These differences are used to identify species.

Forelius mccooki (above) and Dorymyrmex flavus (below)

Forelius mccooki (above) and Dorymyrmex flavus (below)

The red arrow indicates the cone or pyramid on Dorymyrmex. This structure is diagnostic for the genus.

The red arrow indicates the cone or pyramid on Dorymyrmex. This structure is diagnostic for the genus.

Forelius mccooki

Forelius

Solenopsis invicta: This is the invasive, red imported fire ant. Note the antennae have a two-part club at the end and altogether there are 10 segments on each antennae. These features are diagnostic for the genus.

Solenopsis invicta collected from baits in the Fort Worth Nature Center.

Solenopsis invicta collected from baits in the Fort Worth Nature Center.

RESULTS:

Sample # Species Count
1 Solenopsis invicta  3
2 Crematogaster cerasi 2
3 Crematogaster cerasi 2
Dorymyrmex flavus  1
Forelius mccooki 18
4 Forelius mccooki 18
5 Crematogaster lineolata 6
Forelius mccooki 16
6 Camponotus americanus 1
Solenopsis invicta 1
Unknown 1
7 Forelius mccooki 3
Solenopsis invicta 1
8 Forelius mccooki 47
9 Solenopsis xyloni 3
10 Forelius mccooki 89
11 Crematogaster lineolata 4
Forelius mccooki 1
12 Solenopsis invicta 1
13 Forelius mccooki 2

Video clip #1: “Bug and Ants”

This clip shows many Forelius ants on a tuna bait. An insect, perhaps a bug, lands on the bait and interacts with these ants, then leaves. It looks like the ants may be performing a cleaning service which has been suggested for Forelius ants in some situations.

Video clip #2: “Crematogaster Waggle”

This clip shows many Forelius ants on tuna bait. A Crematogaster forager is in the lower right hand side. As this forager leaves the bait, she waggles her gaster indicating that she is dispensing a pheromone.
Here are the two short clips from tuna baits that the Trinity Valley School of Fort Worth, Texas set out at the Fort Worth Nature Center.

Stratford and Tandy Hills Prairie Ants

I am completing the ant identifications for the prairie and forest in the Southwest Nature Preserve in Arlington, Texas and the additional prairies, Statford  and Tandy Hills, in Fort Worth, Texas. I believe I have found another Temnothorax species which I have not been able to identify and another Pheidole species. This is quite exciting. No Pogonomyrmex ants are found in the Stratford or Tandy Hills Prairies.

Tandy Hills Prairie, Fort Worth, Texas

Addtional Sampling for Ant Assemblages

One of my committee members suggested I get more samples for my ant assemblage project. I have added three prairie sites and one woodland.

One prairie and one woodland site are in the Southwest Nature Preserve in Arlington, Texas. The Comanche harvester ant is nesting in this prairie. There are about 50 colonies of Pogonomyrmex comanche. Soil here is mixed but very sandy with some bare ground.  Currently working through these samples.

Prairie Site at the Southwest Nature Preserve, Arlington, Texas

Prairie Site at the Southwest Nature Preserve, Arlington, Texas

The woodland site at the Southwest Nature Preserve, Arlington, Texas

The woodland site at the Southwest Nature Preserve, Arlington, Texas

Today I set pitfall traps in the Tandy Hills Prairie and Stratford Prairie in Fort Worth, Texas. Comanche is not found in these sites. The soil here is dark and rocky, more clay and little sand, and no bare ground. I will collect these samples on Tuesday and see what I’ve got.

Tandy Hills Prairie Site, Fort Worth, Texas

Tandy Hills Prairie Site, Fort Worth, Texas

Stratford Prairie Site, Fort Worth, Texas

Stratford Prairie Site, Fort Worth, Texas

 

Turret and nest of Trachymyrmex turrifex, Fort Worth Nature Center, Fort Worth, Texas.

Trachymyrmex ants

In my prairie sites where I study the Comanche harvester ant, I have found two species of Trachymyrmex: T. septentrionalis and T. turrifex. I have 14 prairie sites and of these 8 have both species, 5 have only T. turrifex and one has only T. septentrionalis. Finding both species is quite exciting for two reasons: first, these are funky looking ants with all kinds of spiny projections on their bodies. So, they were one of the first ant genera I learned to identify correctly. And they are very cute. But the more exciting thing has been the discovery of the nests of T. turrifex, which are turrets. They have a bit of a crater area in the middle of which is this turret, about 2 and ½ inches long. I was quite astonished when I happened upon some of these structures and more so when I saw ants coming in and out of them. I got some photos and some video as well.

Turret of Trachymyrmex turrifex, Fort Worth Nature Center, Fort Worth, Texas. This turret is about 2 inches tall.

Turret of Trachymyrmex turrifex, Fort Worth Nature Center, Fort Worth, Texas. This turret is about 2 inches tall.

The nest of T. septentrionalis is very different. The entrance is a few centimeters from a characteristic crescent shaped pile of soil which they make as they excavate their nest.

Trachymyrmex septentrionalis nest, Fort Worth Nature Center, Fort Worth, Texas

Trachymyrmex septentrionalis nest, Fort Worth Nature Center, Fort Worth, Texas

These differences in nest form, and ant nest architecture in general, are quite interesting to me. I have no idea what the differences in form between these two Trachymyrmex species are about — they are living in the same kinds of habitats and I believe have similar life patterns, etc. So, these nest differences are quite a mystery.

Earlier this summer, I found some Solenopsis xyloni easily coming and going in and out of a T. septentrionalis nest. The S. xyloni, a native fire ant species, and T. septentrionalis met each other at the entrance to the Trachymyrmex nest without out any sign of aggression and the S. xyloni preceded to enter the nest. Trachymyrmex expert Dr. Jon Seal (University of Texas-Tyler) has observed the same but does not know what is going on.

Trachymyrmex septentrionalis nest maintenance workers, Fort Worth Nature Center, Fort Worth, Texas

Trachymyrmex septentrionalis nest maintenance workers, Fort Worth Nature Center, Fort Worth, Texas

Solenopsis xyloni (smaller, shiny ant, lower) and Trachymyrmex septentrionalis (larger, rough looking ant at top) at the entrance to the T. septentrionalis nest.

Solenopsis xyloni (smaller, shiny ant, lower) and Trachymyrmex septentrionalis (larger, rough looking ant at top) at the entrance to the T. septentrionalis nest.

Trachymyrmex ants are related to the leaf cutter ants in the genera Atta and Acromyrmex. Though technically, not leaf cutter ants, Trachymyrmex ants may collect leaves to grow fungus like the true leaf cutter ants. But my understanding from Jon Seal is that Trachymyrmex ants are not obligate fungus eaters. They forage on other foods as well.