Ant identification: July 2010 Archives

In most cases anything that looks like an ant is an ant. But there are also many insects and arachnids that mimic ants. Read on to learn more about this amazing mimicry.

Ants are incredibly abundant and dominant organisms throughout the world. Conservative estimates of their worldwide numbers range from 1 million billion to 10 million billion and between 15% and 20% of terrestrial animal biomass is ant biomass. Their huge numbers and ecological dominance make them attractive targets for other animals to parasitize in any way they can.

More than 2000 arthropod species, including many spiders, hemipteran bugs, and staphylinid beetles have evolved to look and behave just like ants in order to blend in and be accepted into colonies. Once there, they may derive protection from being surrounded by friendly ants, they may steal food from the colony, or they might even prey upon the ants and their eggs. Check out this post on velvet ants to find out about a type of wasp that sometimes mimics ants but is often confused with them.

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These Salticid spiders are ant mimics. Notice how they use their front pair of legs as "antennae" because they do not have true antennae. Photos from http://natural-japan.net/?cat=35 and http://en.wikipedia.org/wiki/Ant_mimicry



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The ant Pseudomyrmex salvini (left) and a mimicking spider in the genus Synemosyna (right). Photos courtesy of D. Ballhorn.



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The ant-mimicking spider, Aphanlochilus rogersi, with a captured Cephalotes pusillus. Photo from http://www.alexanderwild.com/


This wonderful picture by Alex Wild shows the predatory ant-mimicking spider, Aphanlochilus rogersi, holding one of its victims snatched from a column of foraging Cephalotes pusillus. These spiders are so specialized as predators of these ants that they refuse to eat other types of insects. They not only blend in with ants by looking like them, they will also hold their catches in a way that makes it look like they are just another member of the colony holding a deceased companion. But looking like ants can also help arthropods in a very different way.

It turns out that most ant mimics do not eat ants. So then why do they look exactly like them? Many species of ants are aggressive, well armed with stingers and a powerful bite, are often distasteful, and have the amazing ability to recruit their nestmates to help when they are attacked. These features along with their huge abundance make them intimidating to predators and ideal models for other, less well protected, species to mimic.

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Though it looks very similar to an ant, this is actually a cricket in the genus Macroxiphus. Photo from http://en.wikipedia.org/wiki/File:Macroxiphus_sp_cricket.jpg.


In order to successfully integrate themselves into colonies, many ant mimics hide out in the ant nest that they plan to infiltrate for days before exposing themselves to the ants living there in order to absorb the smell of the nest. Ants depend largely on smell to identify nestmates, particularly in the darkness of the colony interior, so by smelling like the nest, mimics protect themselves even further. Recently, it was found that an ant larvae mimicking butterfly, Maculinea rebeli, actually mimics ant acoustic signals as well! The larvae of these butterflies mimic the scent and begging behavior of ant larvae and are carried into nests by unsuspecting ants. Once there, they start making sounds very similar to ant queens. Using this sound means that they are treated even better than the average ant larva because the nurse ants think that they are royalty!

Though termites do not mimic ants, they are often confused with them because they are both social insects that live together in large colonies. Check out our post on termites to find out more about them.

The many types of ant mimicry in a variety of organisms makes ants seem even more impressive. Everybody seems to want to be like them.

Ben Rubin & the AntAsk Team

Hello,

I'm trying to decide whether to exterminate the ants living in grass/twig/leaf mounds around my property. If they are not native I intend to try to eliminate them.
I live about 30 minutes outside of Portland, Oregon at about 1500ft elevation. My land is mostly wooded but with grassy, sunny areas with orchards trees and garden areas. Over several acres there are at least 6 ant mounds each 6-24" tall and 12-24" across in the grass or at the edges of the woods.

The ants have red heads and near black bodies. They are about 1/4" long (not less than that but not close to 1/2"). From looking over some ID keys online here's what I know to look for that describes these ants:

Petiole with 1 node and is very distinct (spiky)
Thorax is uneven
Head is red and thorax and abdomen are black or very dark brown
Antennal clubs are indistinct (or absent)
Eyes are black
No stinger is visible
Seem to be two (maybe three) black dots between the eyes and much smaller than the eyes.

If there's a good resources that you can point me toward to do my own research that would be great too.

I hope that you might be able to help.

Thanks much,
Joshua (Portland, Oregon, USA)


Dear Joshua,

Thank you for the very detailed and helpful description of the ants you are finding on your property. This really helps to narrow down the ants you are likely finding. From your notes on the ants themselves and their mounds it sounds like you likely have Formica (wood ants). You can see images of many of the species here and here.

These are likely native species and although their nests can be unsightly on a well-manicured lawn they are no threat to you, your children or pets, or home. The species you are finding probably belongs to the "Rufa group".

To identify ants you find on your property in the future, I would recommend "Ants of North America: A Guide to the Genera" by Brian L. Fisher and Stefan P. Cover.

Thanks for contacting us and keep enjoying your native ant fauna,
Corrie Moreau & the AntAsk Team

Dear ant experts,
I found these large ants yesterday in my backyard. I have never seen them before.

No one I know has been able to identify them.
I was hoping you could identify them and tell me a little about them.
Through observation these are some details I can tell you about them.

Their color appeared to be a pearlescent orange red color in sunlight.
They were about an inch in length.
The appeared to be rather thick for an ant.
Some were winged and others not winged.
I tried to capture one and they were quick and evasive.
I live in Palmdale, California which is located in Mojave desert, high desert area.

I have uploaded the pictures on photobucket. Here are the links:

http://i807.photobucket.com/albums/yy357/noinfoneeded/DSCF0308.jpg?t=1279386160
http://i807.photobucket.com/albums/yy357/noinfoneeded/DSCF0299.jpg?t=1279386160
http://i807.photobucket.com/albums/yy357/noinfoneeded/DSCF0304.jpg?t=1279386238
http://i807.photobucket.com/albums/yy357/noinfoneeded/DSCF0307.jpg?t=1279386273

Thank you in advance,
Efren
Palmdale, California


Dear Efren,

Thank you for contacting AntAsk and including photos of your mystery ants! Not only do the photos really help us with identifications, but also knowing where you live really helps us narrow the list of possible ant species.

From the photos and description you sent of the ants you are finding in your backyard, it looks to me like you are seeing species of harvester ants from the genus Pogonomyrmex. Although it is difficult to tell exactly which species you are observing, it seems you are likely finding either P. californicus or P. rugosus, but you can see a list of all the species of Pogonomyrmex found in California on AntWeb here.

You can also see additional photos of each Pogonomyrmex species and distribution maps here.

Pogonomyrmex ants are called "harvester" ants because they collect seeds to feed on (called granivory). You can often find them carrying seeds back to their nests and ant photographer, Alex Wild, has some great photos of this behavior on his website here.

You mentioned that you saw both winged and non-winged individuals. The winged ants are the female and male sexuals getting ready to go on their nuptial mating flight. You can read more about this on a previous AntBlog post here.

On a last note, I should mention that harvester ants are often known for their painful stings, so be careful when trying to collect them. Remember that ants, like most animals, usually only hurt humans when they feel threatened. So as long as you are not trying to pick them up or dig into their nest, you are not likely to be stung. Enjoy their beauty and remember that they are part of the native habitat and serve many useful services in the ecosystem (including dispersing seeds).

Thanks for sharing your ant photos!
Corrie Moreau & the AntAsk Team

Hi there,

I live in Brisbane in Australia, and recently a species of ant has been snooping around a pot plant in my first floor apartment.

I haven't been able to figure out what sort of ant it is, but I'd be interested in finding out.  I also have house ants sneaking in the same area (which I'm trying to discourage as they bring in aphids) and the two species seem to get along just fine.

I've attached a few pictures to help with identification.

Many thanks,
Caroline
Brisbane, Australia


Dear Caroline,

Thank you for contacting AntAsk and sending photos regarding the ants you have in your apartment in Brisbane, Australia.  There are actually quite a few helpful resources for identifying ants in your region.  I will include some links below, but I think the resource that would be most helpful is a small pocket guide book "Ants of Brisbane" available at the Queensland Museum in Brisbane (and likely in other bookstores): http://www.southbank.qm.qld.gov.au/en/Shop/Books/Pocket+Guides/Ants+of+Brisbane

It appears to me that the ants you are finding in your plants belong to the genus Polyrhachis, sometimes called "spiny ants":

http://www.brisbaneinsects.com/brisbane_ants/golden_ant.htm

These ants do not sting and are rarely aggressive.  As they can tend plant feeding insects for honeydew, this is likely the reason you are finding them on your houseplants. Here are some more useful links to ants in Australia (sometimes these links need to be reloaded several times to work, so be patient):

http://anic.ento.csiro.au/ants/
http://www.brisbaneinsects.com/brisbane_ants/

If you know where the ants are coming into your home, you could try to discourage them from coming in.  This can be done several ways including making sure their food sources are unavailable. In this case you will need to make sure you get rid of all plant feeding insects such as aphids, scale insects, etc. Another option would be to block them from coming into your home. There are many products available for this at your local hardware store, but you could also try using a very fine, silty powder (such as cinnamon, cayenne pepper, diatomaceous earth, corn starch, etc.) to plug any holes the ants are using to come into your home.

Thanks again for sending photos of your beautiful ants!

Corrie Moreau & the AntAsk Team

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