Subfamily FORMICINAE
Tribe PLAGIOLEPIDINI
Brachymyrmex depilis Emery

by Joe A. MacGown, uploaded 3 November 2009, last updated on 14 July 2015

Brachymyrmex depilis, frontal view of head of a worker (photo by Joe A. MacGown)

Brachymyrmex depilis, full face view of the head of a worker (Photo by James Lewis and Joe A. MacGown)

Brachymyrmex depilis, profile view of the head of a worker (Photo by James Lewis and Joe A. MacGown)

Brachymyrmex depilis, dorsal view of the head of a worker (Photo by James Lewis and Joe A. MacGown)

Brachymyrmex depilis, full face view of the head of a queen (Photo by James Lewis and Joe A. MacGown)

Brachymyrmex depilis, profile view of the head of a queen (Photo by James Lewis and Joe A. MacGown)

Brachymyrmex depilis, dorsal view of the head of a queen (Photo by James Lewis and Joe A. MacGown)

Introduction
Brachymyrmex is a New World genus whose members are minute, soft-bodied, have a small petiolar scale, and a nine segmented antenna without a club. Workers have well developed eyes. Color ranges from pale light-yellow to dark brown. Species is this genus usually nest in soil or rotting wood. This group is in drastic need of revision.

Taxonomic History (provided by Barry Bolton, 2013)

Brachymyrmex heeri subsp. depilis Emery, 1893: 635 (w.q.) U.S.A. Nearctic. Wheeler & Wheeler, 1953: 139 (l.). Raised to species: Santschi, 1923: 663. Senior synonym of Brachymyrmex nanellus: Creighton, 1950: 359; of Brachymyrmex flavescens: Cole, 1953: 266.

Identification
Brachymyrmex depilis is a small yellow species that lacks erect hairs on the body and limited pubescense. The head is wider than long. The eyes are relatively large for such a small species with 16 to 20 facets, and 6-or more in greatest diameter. The scape barely surpasses the occipital border. Metanotal sutures are reduced or not obvious.

Brachymyrmex depilis is distinguished from other species in the group in this region by its lack of erect hairs (only a few on the edges of the gastral tergites) and relatively large eye. An undescribed species known only from FL is similar in that it lacks erect hairs, but the eye is much smaller with only 3-4 facets in the greatest diameter of the eye. Other yellow species known from the U.S., including a new species that has been collected from southern AL and MS, differ in that they have semi-erect hairs present on the promesonotum. Other species of Brachymyrmex known from this region are dark brown.

Biology and Economic Importance
This species is common in the Southeast in certain forested habitats, especially mixed forests with at least some terrain. However, it appears to be lacking in flatwoods areas, Black Belt Prairie remnants, and fields. Alates have been collected in mid to late June.

Distribution
Range United States, S Canada, Mexico. Most U.S. states and south into Mexico. This species is putatively wide ranging. A badly needed taxonomic revision of the North America forms will likely reveal Brachymyrmex depilis is a number of distinctive species (Anonymous. 2015). In the southeastern US, this is a common species in rich forests founnd in AL, AR, FL, GA, LA, MS, NC, SC, and TN.

Literature Cited
Anonymous. 2015. Antwiki: Brachymyrmex depilis. Online at: http://www.antwiki.org/wiki/Brachymyrmex_depilis. Accessed 14 July 2015.

Creighton, W. S. 1950. The ants of North America. Bulletin of the Museum of Comparative Zoology 104:1-585.

Cole, A. C., Jr. 1953g. Studies of New Mexico ants. V. The genus Pheidole with synonymy (Hymenoptera: Formicidae). Journal of the Tennessee Academy of Science 28:297-299.

Emery, C. 189. Beiträge zur Kenntniss der nordamerikanischen Ameisenfauna. Zoologische Jahrbücher. Abteilung für Systematik, Geographie und Biologie der Tiere 7:633-682.

Santschi, F. 1923. Revue des fourmis du genre Brachymyrmex Mayr. Anales del Museo Nacional de Historia Natural de Buenos Aires 31:650-678.

Wheeler, G. C.; Wheeler, J. 1953. The ant larvae of the subfamily Formicinae. Annals of the Entomological Society of America 46:126-171.

Links
AntWeb Images
Antwiki