Dorymyrmex bicolor
Dorymyrmex bicolor is one of the ants that
are responsible for the classic conical ant nests which occur in the sand
and gravel on the sides of sidewalks and roads. The nests
are usually about 4-5" in diameter, rising up 2-3" to form a volcano
shape. The ants are fond of nesting in cracks in the road and sidewalks.
They can also often be found nesting within the cleared gravel area
surrounding harvester ant mounds. This is especially surprising when you
consider the general pugnacity and irritability of most harvesters. I was
surprised the first couple of times that I saw this, but both Wheeler
(1910) and Creighton (1950) were familiar with this habit and remarked
upon it.
On the left is a photograph of a Dorymyrmex bicolor on a centimeter ruler. D. bicolor is one of the larger of the (few) Dolicherine ants with which I am familiar - most of the other species I commonly see are only a couple millimeters long. If you look on the thorax, you can see the prominent cone from which they derive their generic name. Here is a 560KB QuickTime video of a Dorymyrmex bicolor examining a fragment of an insect leg. |
 One of the
secrets of Dorymyrmex bicolor's cohabitation
with Pogonomyrmex may be one of the traits
that they share with the rest of the Dolicherinae - they spray noxious
chemicals out of their vents. Ants of the Formicinae, many of whom spray
formic acid, often have a round vent (acidopore) surrounded by a fringe of
hairs. As may be seen in the picture at the right,
Dorymyrmex bicolor's vent is slitlike. |
 To the right
are a couple of pictures of D. bicolor at
higher magnifications, providing a clearer view of the thoracic cone. |