Subfamily DOLICHODERINAE
Tribe DOLICHODERINI

Dorymyrmex bureni (Trager)
pyramid ant
Dorymyrmex bureni, frontal view of the head of a worker
(click image to enlarge).
Dorymyrmex bureni, side view of a worker
(click image to enlarge).
Typical crater mound surrounding the entrance to a Dorymyrmex bureni nest
(click image to enlarge).

Overview
Members of the genus Dorymyrmex, similar to many other dolichoderine ants, have thin and somewhat flexible integument, a single petiolar node, and lack a sting. They can be differentiated from other dolichoderine ants by the propodeum being pyramidal or cone shaped (on dorsum); the presence of grouped flexuous elongate hairs along the underside of the head (this grouping of hairs is call a psammophore); and the third maxillary palp being as long as the fourth and fifth segments combined. They typically make colonies in the soil in open areas, and often have distinctive crater-like mounds (see the photo above). They are predaceous and often litter their mounds with the bodies of various insects, especially other species of slain ants. Similar to other dolichoderines, they emit an unpleasant odor.

Common names
Pyramid ants, crater ants

Identification
Worker: Overall length approximately 3.0 to 3.5 mm. Color, yellowish-orange to orangish-brown with antennal funiculus brownish (except first segment, which is usually lighter) and posterior portion of gaster brownish. Shiny in overall appearance. Head longer than wide, HL 0.85-1.05 mm and HW 0.71-1.00 mm (measurements from Trager, 1998). Promesonotum smoothly convex in profile. Propodeal cone somewhat low and blunt.

Queen: Overall length approximately 6.5 mm. Color, darker orangish-brown with funiculus brownish (except first segment, which is usually lighter) and posterior portion of gaster brownish. Integument dulled by dense pubescence.

Male: May be separated from the similar Dorymyrmex flavus by its larger ocelli, which are smaller in the day flying D. flavus.

This species is can be identified in the field by its yellowish coloration, long legs and scapes, fast movement, and by its preference for sandy soils.

Dorymyrmex bureni may be confused with D. flavopectus, which differs by having longer antennae and by having a dark brown head and gaster that contrasts with the yellowish colored alitrunk. Another similar species is D. flavus, which is typically more western in distribution and usually has an angular mesonotum (best seen in profile view).

Biology and Economic Importance
Dorymyrmex bureni is a common species in the Southeast and is typically found in open disturbed habitats, especially in sandy areas, but also in coastal dunes or other natural sand habitats. This species is active diurnally and may be seen foraging throughout the year on warm days. We have observed them foraging in Mississippi during the hottest parts of the day in the summer. Colonies are relatively deep and surmounted by a crater shaped mound (see photo above). It is not unusual to find several to many colonies in close proximity to one another. Workers are extremely fast moving. We have observed this species to attack workers and especially newly mated queens of the imported fire ants, the bodies of which are then often scattered around the crater of the Dorymyrmex colony. According to Trager (1988), mating flights usually occur on warm nights, sometimes after a rain, from spring through the fall with the highest activity being at dusk.

It is not uncommon to find mixed colonies of D. bureni and D. smithi. Trager (1988) states that D. smithi (D. medeis in his paper) is a temporary social parasite of D. bureni.

This species is not considered a pest or nuisance species as it does not frequent man-made buildings, does not sting or readily bite, and does not shoot noxious formic acid as in some formicine ants. In fact, the species would be considered beneficial by most people due to its predatory behavior, which may provide some amount of biological control of pest species (Trager, 1988) including its ability to hold its own against the imported fire ants.

Distribution
Alabama, Florida, Georgia, Louisiana, Maryland, Mississippi, North Carolina, South Carolina, Texas, Virginia (Davis, 2011; MacGown, 2011; ;Snelling,1995; Trager, 1988).

Literature Cited
Davis, 2011. AntWeb: Texas Ants. Available online at: http://www.antweb.org/texas.jsp [accessed 18 January 2011].

MacGown, J. A. 2011. Ants of the Southeastern United States (species list). [accessed 18 January 2011].
http://www.mississippientomologicalmuseum.org.msstate.edu/Researchtaxapages/Formicidaepages/faunal.lists/
Southeastern.species.htm

Snelling, R. R.  1995. Systematics of Nearctic ants of the genus Dorymyrmex (Hymenoptera:  Formicidae). Contr. Sci. (Los Angel.).  454: 1-14.

Trager, J. C. 1988. A revision of the Conomyrma (Hymenoptera: Formicidae) from the southeastern United States, especially Florida, with keys to the species. Florida Entomologist 71: 11-29.

Links

AntWeb
Discover Life Images
BugGuide: Species Dorymyrmex bureni