Ants - Formica - BugGuide.Net

Formica sp. (pallidefulva group) - workers

Shape of alitrunk (i.e., apparent thorax)and presence of ocelli in workers rules out otherwise very similar Camponotus castaneus. Maybe Formica pallidefulva itself.

… Richard Vernier, 31 March, 2008 - 7:08pm

....

Do I need to get rid of these ? Are they a threat of any kind (they're in my yard) ?

… Sam Houston, 1 April, 2008 - 8:10am

To "get rid"...

I don't think you need. This species normally doesn't invade inside of houses or livings. It nests in earth and only very rarely - if ever - in woody material. Its diet is in large part insectivorous, as you could witness with the Cuerna leafhopper.
If these ants should present a threat of any kind, this would only be in two ways:
- a nuisance per themselves, by their agressivity and tendency to bite.
- by tending Aphid colonies on some plants of your garden.
Therefore, you may need to control their growth, but not necessarily to wholly extirpate them.

… Richard Vernier, 1 April, 2008 - 2:12pm

Ok, thanks.

There were two entrances about 15 feet apart. Will their nest expand any further ?

… Sam Houston, 1 April, 2008 - 2:19pm

15 feet (or roughly 5 m) apart...

seems to be fairly far away, even for such swift-running ants.
Are you sure the two entrances do communicate each other and workers are mutually tolerant? If so, this would suggest a so-called polydomous colony, with several queens. Such "federations" are indeed prone to expansion and virtually perennial, contrary to monodomous colonies.

… Richard Vernier, 1 April, 2008 - 10:05pm

Yes

There was a constant stream of ants going back and forth between the two holes.

… Sam Houston, 2 April, 2008 - 8:36am

The Formica pallidefulva grou

The Formica pallidefulva group was recently revised taxonomically. See this article for all the gory details: http://antbase.org/ants/publications/21293/21293.pdf .

Anyway, your ant appears to be the recently described F. biophilica, a common species in the Southeast, west to Texas and Oklahoma.

… James C. Trager, 4 June, 2008 - 3:09pm