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Ants of Tucson, Arizona: Crematogaster opuntiae

There is a story on the Internet of a myrmecologist (unfortunately unnamed) finding 10 species of ants, including army ants, while waiting for a flight at the Tucson, Arizona airport. I had two hours in Tucson on Saturday morning, so I wondered if I could do as well. For the next few days we'll see if I was up for the challenge.

The first ant I found was a worker of the genus Crematogaster, named for its lovely heart-shaped rear section or gaster. This cutie is Crematogaster opuntiae, a specialist often found feeding on the extrafloral nectaries of cacti. This particular cactus is a cholla, Cylindropuntia.

Although Crematogaster opuntiae workers are known for chasing herbivores away from cacti in defense of the extrafloral nectaries, they are also predators of other insects, such as termites.

For more information, try:

Charles H. Pickett and W. Dennis Clark. (1979).The Function of Extrafloral Nectaries in Opuntia acanthocarpa (Cactaceae) American Journal of Botany. 66(6):618-625.

Discover Life has a photograph of Crematogaster opuntiae raiding termites

Alex Wild also has some fabulous photographs

Finally, if your French is good, Fourmis et Cactus à Nectars Extra-Floraux


4 thoughts on “Ants of Tucson, Arizona: Crematogaster opuntiae

  1. Amy Verdugo

    Can these ants be found in az? I think i found a huge nest of them around a school in a tree. The tree is old of my dad. It may even be rooting. They are fast and sometimes live in the ground. I look at the tree with a flash light and they are running around trying to cover the holes with leaves and branches. They do not come out when it is cold. They also have shiny bottox areas and i thought they were honey pot ants but i see their red bodies and black bottox areas and started researching. Pretty cool ants. I am fascinated by them. They have their babies look out and guard. Let me know please.

  2. Bob Moreau

    I live in the Davis Mountains, West Texas at 6000 feet. I have dozens of chollas and they are all inhabited by what looks like crematogaster opuntiae. When I approach cautiously I always see a very few ants. As soon as I disturb the plant they appear in quantity where less than a minute ago there were none! Where do they come from so quickly? I have tried to see them emerging from holes or whatever, but I'm old and can't see that well. Do they live within the cactus? I haven't seen any obvious holes. Thank you.

  3. Roberta

    Sorry it took me so long to get back to you.

    The ants live in the ground, but their nests are hard to find because they are most active a night. According to one article, the scientists mixed colored UV powder with baits so they could follow the ants back to their nests with a UV light at night.

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