Wild About Ants » Ant Facts

Ants Raiding Wasp Nest

Roberta — Sat, 09 Jul 2011 01:40:30 +0000

Photographs from the archives.

The nest belongs to common Polistes paper wasps. Paper wasps are supposed to produce a secretion that they spread on the petiole of the nest (the thin strand that fastens the nest to the substrate) to deter ant predators. Obviously the secretion failed this time. (The link takes you to a photograph of an intact nest).

Ant Mystery Revealed: Lasius and Aphid Eggs

Roberta — Fri, 29 Apr 2011 12:45:38 +0000

Did you figure out what the black ovals from the photograph in the recent Lasius post were?

Although aphids give birth to live offspring during parts of their life cycle, they also lay eggs during certain stages. Those stacks of black ovals are root aphid eggs tended by Lasius ants.

The following excerpt from Applied Entomology: An Introductory Text-book of Insects in Their Relations by Henry Torsey Fernald (1921) talks about the life cycle on one root aphid, the corn root aphid:

Note: This book is now out of copyright. The excerpt is from Google Books.

Have you ever seen ants tending the eggs of another species?

Ants Caught Napping

Roberta — Sun, 27 Feb 2011 17:02:10 +0000

If you have ever watched the ants in an ant farm, you have probably noticed ants sitting around seemingly doing nothing. This leads to the question: are the ants sleeping?

Whether or not social insects sleep is a question that has gotten some definitive work in the bees. In fact, there are bees that are affectionately called “sleeper bees” for their behavior of resting on plants in clusters over night.

For example, these long-horned bees of the tribe Eucerini (named for the long antennae present on males), are often seen resting in clusters on plant stems. Other bees and even wasps have been known to “sleep” over night in flowers.

Recently, Klein et al. conducted an experiment on sleep in honey bees. They showed that depriving worker honey bees of sleep during the night, using a magnetic device, actually effects their ability to perform waggle dances the next day. Discover Magazine has an article with a brief video of sleepy bees dancing, shown here (with a sponsor ad at the end).

What about ants? Do ants sleep?

Many myrmecologists have noticed that a certain portion of ants in laboratory colonies spend a lot of time doing nothing. Blaine Cole (1986) reported that workers of the ant Leptothorax allardycei spent up to 55% of their time resting, which he called quiescent. Nigel Franks’ group writes that Leptothorax acervorum workers in the nest are inactive for 72% of the time and and foragers 15% of the time (Franks et al. 1990) and that Temnothorax albipennis workers are inactive about the same percentage of time in small colonies (44%) as in large colonies (46%) (Dornhous et. al. 2009).

None of these scientists have actually gone as far as to say these ants are sleeping though.

Deby Cassill in 2009 broke with tradition and calls certain periods of rest in ants “sleep.” Working with fire ants, she videotaped ants in an artificial nest. She created an artificial colony with three queens, 30 workers and 30 larvae. Checking the posture and position of the antennae, she concluded that queens sleep 90 times per day for 6 minutes per nap, whereas workers dosed 250 times per day for roughly one minute at a time. You can see a video of the set-up at the BBC Earth News.

Cassill even went as far as to label Rapid Antennal Movements (RAM) as the invertebrate equivalent to Rapid Eye Movement (REM) sleep in vertebrates. Her conclusion: yes, ants sleep.

Ant napping?

Are we ready to agree?

1. What do you think about the studies that observe ants spend a lot of time doing nothing?

My thoughts: One thing that is immediately apparent in contrasting the honey bee studies with the ant experiments is that an artificial honey bee hive is much more “natural” than a laboratory ant nest. In a demonstration hive the bees usually have access to outside foraging, they have comb, they are going about their business as usual.The ants, on the other hand, have no soil to move, no myrmecophiles to interact with, no predators, no opportunity to move brood to optimal locations, etc. etc. It seems evident that greatly reducing the number of available tasks at hand limits the conclusions that can be made about the behaviors observed.

2. Can ants, or even insects, sleep?

My thoughts: Seems like a reasonable idea, especially looking at the honey bee study.

3. What do you think of the “power nap” finding with fire ants?

My thoughts: Having spent some time filming ants, I know that they are sensitive to vibrations we humans do not even notice, such as the laboratory incubators coming on and off in the room next door. I don’t have a copy of the paper yet. Does anyone know whether Cassill placed her artificial nests in such a way to minimize artificial disturbances, for example, placed them on vibration dampening pads? If not, it seems possible that something was disturbing those ants to keep them awake more often than usual.

What do you think?

References:

Barrett A. Klein, Arno Klein, Margaret K. Wray, Ulrich G. Mueller, and Thomas D. Seeley. 2010. Sleep deprivation impairs precision of waggle dance signaling in honey bees. Proceedings of the National Academy of Sciences (PNAS). 107 (52): 22705-22709.

Deby L. Cassill, Skye Brown, Devon Swick and George Yanev. (2009), Polyphasic wake/sleep episodes in the fire ant, Solenopsis invicta. Journal of Insect Behavior. 22 (4): 313-323.

Cole B. (1986). The social behavior of Leptothorax allardycei (Hymenoptera,
Formicidae): time budgets and the evolution of worker reproduction. Behav Ecol Sociobiol. 18:165–173.

Anna Dornhaus, Jo-Anne Holley and Nigel R. Franks. (2009). Larger colonies do not have more specialized workers in the ant Temnothorax albipennis. Behavioral Ecology. 20 (5): 922-929. (full text available online free)

Nigel R. Franks, Steve Bryant, Richard Griffiths and Lia Hemerik. (1990). Synchronization of the behaviour within nests of the ant Leptothorax acervorum (fabricius)—I. Discovering the phenomenon and its relation to the level of starvation. Bulletin of Mathematical Biology. 52( 5): 597-612.

Do Fire Ants Tend Aphids?

Roberta — Tue, 01 Feb 2011 01:01:05 +0000

I got a question from another entomologist this week: Do fire ants tend aphids?

At first this seemed straightforward enough. Sure they do. It’s mentioned in the literature (see below). Although I couldn’t recall ever seeing our local Solenopsis xyloni tending aphids, we don’t get all that many aphids here.

Delving a bit deeper, I decided to see if I could find an image of fire ants tending aphids. Our local Arizona Cooperative Extension did me proud, in their article A Fire Ant Smorgasboard.

Except, of course, I’m pretty sure those aren’t fire ants. Aren’t they acrobat ants (Crematogaster)?

Well, at least they aren’t the only ones to mistake another ant for fire ants. Over at 6Legs2Many she has a whole post full of “Things that are not fire ants.” Too fun.

On a more serious note, I suspect because fire ants have underground foraging tunnels, they may “tend” to specialize on root-feeding homoptera.

Any thoughts?

References:

Thomas Rossiter Barnum (2008) Recruitment to and defense of aphids by fire ants and native ants and an estimate of their trophis positions using stable isotopes. M.S. Thesis, Auburn University.

Ian Kaplan and Micky D. Eubanks. (2005). Aphids alter the community-wide impact of fire ants. Ecology, 86(6): 1640–1649

Ants and Peonies

Roberta — Wed, 22 Dec 2010 16:26:20 +0000

From the photo archives:

You have probably heard all about the relationship of ants and peony flower buds.

Peonies (Paeonia sp.) are small perennial shrubs that produce large, lovely flowers in the spring. The flower buds produce nectar via extrafloral nectaries, which attract ants. The ants chase off potential herbivores until the buds open. A simple story, yet an entire garden mythology has grown up around it. You can do an Internet search for “peony ants” and find a wealth of funny, and at times sad, myths.

But there may be another piece of the story that is rarely mentioned.

Do you know what this plant structure is? (Quit looking at the ant )

Since I already mentioned peonies, you can probably guess it is the fruit of a peony. Inside each of those three “pods” are rows of seeds completing development.

As this is not a bud, what is an ant doing there? Take a look at the next few photographs and see what you think.

Mandibles agape…

Do you see the fly?

Has anyone seen this before? Do you know if the extrafloral nectaries are still active? Are ants just poor botanists?

If you want to find out more, try:

B L Bentley. (1977). Extrafloral Nectaries and Protection by Pugnacious Bodyguards. Annual Review of Ecology and Systematics, Vol. 8: 407 -427.

Life of Ants

Roberta — Wed, 22 Sep 2010 16:24:22 +0000

There’s only one problem with using a hose as an evacuation route…

Eventually you reach the end of the line!

Thank you to Karen Gibson for sending these photographs and giving me permission to use them.

Where to Find Queen Ants

Roberta — Wed, 25 Aug 2010 01:49:05 +0000

Many people want to know where they can find a queen ant.

Here in Phoenix the ant nests are filled with alates (winged ants) ready to swarm in late July and August.

In the day or so after a strong thundershower, called “monsoons” here, it is easy to find queens running across the ground looking for spots to nest.

This week I found a great place to hunt – tennis courts. As the bright overhead lights came on in the evening after a big storm the night before, the queens ants themselves started to rain down. I collected queens of three different species in ten minutes. I wasn’t too interested in the rover ant queens, but noticed they were mating right there on the tennis court. It was amazing.

Unfortunately my tennis buddies were not as thrilled as I was, so I didn’t get a chance to observe as much as I would have liked. You can guess where I’ll hanging out be next time it rains.

Ever found queen ants attracted to the big lights at sporting events?

Where to Get Fluon

Roberta — Mon, 23 Aug 2010 14:35:31 +0000

Now here’s a well kept secret:

Do you know about fluon, the slippery white material that is essential to keep ants where you want them (at least as much as possible)?

It is available at that old standby of insect supplies, BioQuip as

Insect-A-Slip Insect Barrier – Fluon

It isn’t cheap, but you don’t need very much.

Yeah BioQuip!!!

More on Ant Stridulation

Roberta — Mon, 07 Jun 2010 12:19:26 +0000

Awhile ago I did a post about ant stridulation or ants communicating via sound. I recently found a couple more recordings of ants.

The first is a short piece on recording ants for KUER radio in Utah. Dr. Bernie Krause, a bioacoustician, talks about his experience recording in Cherry Creek, AZ in Western Soundscapes: Ants with ant sounds in the background. Unfortunately, he does not identify the ants.

Entomologist Hayward Spangler talks about a novel way of using his teeth as a way to pick up harvest ant stridulations. You can listen and download a mp3 file at NPR: Listening to Ants or listen here to same recording. (In case one of the links breaks in the future.)

You can also hear a recording of the harvester ant stridulations at Western Soundscape Archive

I just can’t get enough of listening to ants. How about you?

Where do ants go in the winter?

Roberta — Sat, 17 Apr 2010 19:13:32 +0000

Once again, our post has been inspired by a children’s book. This time it is Bugs and Bugsicles: Insects in the Winter by Amy S. Hansen and Robert C. Kray (illustrator). The authors follow different insects, including pavement ants, as they prepare for winter. I posted a review of this book at Wrapped In Foil and insects in winter activities at Growing With Science.

When you see ants and other insects coming out in the spring, you may wonder “Where do ants spend the winter?” The answer is, it all depends on where in the world the ants live, and which of the over 12,000 species you are studying.

Where below-freezing temperatures are common, ants exhibit a number of strategies to get by.

Under the ground:

Some ants, like wood ants (Formica), can adjust the structure of their nests to help regulate the internal temperature. The huge mounds act as solar-collectors, increasing the temperature inside. When it becomes too cold, wood ants retreat to deep underground, below the frost line.

In wood:
Camponotus carpenter ants, live in nests in wood. Although wood is a good insulator, it still freezes inside during the winter. Carpenter ant species that live in temperate climates must have a provision for overwintering. The ants enter a state of slowed metabolism called “diapause.” Generally, the queen stops laying eggs. The workers develop large fat bodies, which can be seen as their gasters swell in size. The workers begin to aggregate more than before. In the two species I studied in upstate New York, Camponotus pennsylvanicus and Camponotus novaeboracensis, the larval stage also overwintered in the nest, but pupae and eggs did not.

Although I kept my laboratory colonies at constant temperatures and light conditions, they still periodically went into diapause. It appeared that colonies required exposure to temperatures below 15° C for about 60 days to exit diapause. Without cold temperatures, the colonies would remain in a suspended state for extended periods.

In acorns:
Acorn ants spend the winter inside acorns on the ground. These tiny ants form small colonies. When Joan Herbers and Christine Johnson took a look at how the colonies did over winter, they found low survivorship overall. Why do the ants stick it out in acorns instead of heading underground? Some evidence suggests that by spring acorns are relatively rare, and by staying inside their prize home over winter, the acorn ants are assured of a summer home. (for acorn activities for kids, see Growing With Science).

Winter ants

One species of ant, Prenolepis imparis, has earned itself the name of winter ant because it is often out foraging in temperatures near freezing. Walter Tschinkel showed that in northern Florida these ants actually are active from November to March and then workers seal up their underground nests and don’t come out until the following fall. Leave it to a species of ant to do things completely the opposite to most other insects.

Photograph of Prenolepis imparis from antweb.org (No photographer named)

No winter?

Ants that live in the tropics or hot climates don’t tend to react much to winter, although they may shut down temporarily during a dry or wet season instead. Some ants have extensive nests with elaborate ventilation systems, where the environment inside has uniform temperature and humidity year around. Now that’s the way to live.

Are ants active where you live yet?

References:

Joan M. Herbers and Christine A. Johnson. 2007. Social structure and winter survival in acorn ants. Oikos. 116(5): 829-835.

Tauber, MJ, CA Tauber and S. Masaki. 1986. Seasonal adaptations in insects. Oxford University Press, New York.

Walter R. Tschinkel. 1987. Seasonal life history and nest architecture of a winter-active ant, Prenolepis imparis. Insectes Sociaux. 34(3): 143-164.