Pogonomyrmex subdentatus

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Pogonomyrmex subdentatus
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Pogonomyrmecini
Genus: Pogonomyrmex
Species group: occidentalis
Species: P. subdentatus
Binomial name
Pogonomyrmex subdentatus
Mayr, 1870

Pogonomyrmex subdentatus casent0005720 profile 1.jpg

Pogonomyrmex subdentatus casent0005720 dorsal 1.jpg

Specimen Label

All nests that I have seen were marked by low, irregular beds of sand or gravel with more than one entrance, and contained several hundred workers. The workers retreat rather rapidly toward cover when the nest is disturbed. I have never been able to elicit an attack response. (Cole 1968)

Identification

Pogonomyrmex subdentatus appears to be closely related to Pogonomyrmex salinus, from which it differs in the worker caste largely by the distinctive conformation of the scape base, the greater convexity of the thoracic dorsum, the more variable epinotal armature, the pronounced tooth or lobe on the petiolar peduncle, the broader postpetiole, the weaker cephalic and thoracic punctation, the less dull body surface, and the more shining surface of the first gastric segment which is apparently never either punctate or prominently shagreened. The dorsal thoracic contour of the worker is remarkably convex for a member of the occidentalis complex.

Keys including this Species

Distribution

United States – California, southwestern Oregon, western Nevada.

Distribution based on Regional Taxon Lists

Nearctic Region: United States (type locality).
Pogonomyrmex subdentatus Distribution.png

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Distribution based on specimens

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The above specimen data are provided by AntWeb. Please see Pogonomyrmex subdentatus for further details

Biology

Wheeler and Wheeler (1986) found Anthicus lecontei Champion (Coleoptera: Anthicidae; det. EG. Werner) in a Pogonomyrmex subdentatus nest.

Castes

Worker

Nomenclature

The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.

  • subdentatus. Pogonomyrmex subdentatus Mayr, 1870b: 971 (diagnosis in key) (w.) U.S.A. Cole, 1968: 111 (q.m.). See also: Shattuck, 1987: 175.

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.

Description

Worker

Cole (1968) - HL 1.60-1.77 mm, HW 1.48-1.90 mm, CI 92.5-107.3, SL 1.14-1.37 mm, SI 71.6-76.9, EL 0.42-0.46 mm, EW 0.23-0.27 mm, OI 26.0-26.3, WL 1.63-2.13 mm, PNL 0.38-0.19 mm, PNW 0.38-0.49 mm, PPL 0.38-0.49 mm, PPW 0.53-0.65 mm.

Mandible as shown in Pl. III, Fig. 6; dentition similar to that of owyheei (=Pogonomyrmex salinus); basalmost tooth not offset; basal mandibular margin straight. Base of antennal scape as illustrated in Pl. IV, Fig. 4; apex of superior lobe rather acute; basal flange straight, narrow, rather thin: extending distinctly beyond apex of superior lobe; superior declivity almost straight, meeting the shaft evenly at nearly a straight angle; lip narrow; point absent. Cephalic rugae rather dense, coarse, unevenly spaced; interrugal spaces densely and finely punctate, subopaque.

Contour of thorax, petiole, and postpetiole as in Pl. VI, Fig. 5; thorax notably convex; epinotal declivity short, nearly straight; epinotal armature variable, from denticles to long, sharp spines; contours of petiole and post petiole, in dorsal view, as shown in Pl. VII, Fig. 1; venter of petiolar peduncle with a prominent lobe or blunt spine; ventral process of postpetiole strong. Interrugal spaces of thorax densely punctate, subopaque; dorsum of petiolar and postpetiolar nodes subopaque, finely and densely punctate, with prominent, coarse, widely spaced, wavy, generally transverse fugae. Gaster finely and faintly shagreened. Body color a medium to rather deep ferrugineous red.

Queen

Cole (1968) - HL 1.56-1.71 mm, HW 1.56-1.75 mm, CI 100.0-102.3, SL 1.18-1.33 mm, SI 75.5-76.0, EL 0.42-0.49 mm, EW 0.23-0.28 mm, OI 26.9-28.7, WL 2.09-2.47 mm, PNL 0.42-0.53 mm, PNW 0.49-0.53 mm, PPL 0.42-0.49 mm, PPW 0.67-0.80 mm.

Conformation of mandible and scape base as in the worker. Cephalic rugae rather coarse, widely and unevenly spaced; interrugal spaces subopaque, densely and finely punctate. Thoracic sculpture similar to that of subnitidus; interrugal spaces subopaque. Epinotum armed with a pair of small, distinct, acute angles. Ventral process of petiolar peduncle strongly developed as a prominent lobe. In lateral view, petiolar node with anterior declivity convex; apex acute, with a strong nipple; dorsum flat, in terrupted by rugae. In dorsal view, petiolar node with coarse, widely and irregularly spaced, transverse, subparallel rugae confined chiefly to midregion; interrugal spaces densely punctate, subopaque. In dorsal view, postpetiolar node very densely and finely punctate and rather finely, irregularly, transversely rugose, the punctures tending to obscure the rugae, the surface dull. Gaster very finely shagreened, strongly shining. Body a concolorous, medium, ferrugineous red.

Male

Cole (1968) - HL 1.29-1.33 mm, HW 1.37-1.48 mm, CI 103.8-106.2, SL 0.65-0.76 mm, SI 48.0-51.1, EL 0.49-0.53 mm, EW 0.61-0.76 mm, OI 37.9-39.9. WL 2.13-2.51 mm, PNL 0.38-0.42 mm, PNW 0.49-0.76 mm, PPL 0.38-0.53 mm, PPW 0.68-0.80 mm.

Mandible as shown in Pl. VIII, Fig. 4; with 5 (less often 4) teeth; apical tooth rather short; subapical and basal teeth approximately of same size; ultimate basal tooth not offset from the broadly and evenly concave basal mandibular margin. Cephalic rugae fine, especially around compound eyes, rather closely and unevenly spaced; interrugal spaces subopaque to opaque, densely and finely punctate.

Scutum, scutellum, and sides of thorax rather shining, finely, irregularly, longitudinally striate, the interspaces largely without sculpture; epinotum very faintly, finely, unevenly punctate, delicately striate, moderately shining. Epinotal armature a pair of weak angles. Venter of petiolar node without a process; ventral process of postpetiole strongly developed. Contour of petiole and post petiole, viewed dorsally, as in Pl. XII, Fig. 11. Petiolar and postpetiolar nodes rather shining, densely and strongly shagreened.

Gaster very smooth and shining, without shagreening. Paramere as shown in Pl. X, Fig. 4 and Pl. XI, Fig. 4; apex convex. Head, thorax, legs (except tibiae and tarsi), and antennal scapes dark blackish brown; antennal flagella, tibiae, tarsi, petiole, postpetiole, and gaster notably lighter.

Type Material

Type locality: California.

References

  • Cole, A. C., Jr. 1968. Pogonomyrmex harvester ants. A study of the genus in North America. Knoxville, Tenn.: University of Tennessee Press, x + 222 pp. (page 111, queen, male described)
  • Mayr, G. 1870b. Neue Formiciden. Verh. K-K. Zool.-Bot. Ges. Wien 20: 939-996 (page 971, worker described (diagnosis in key))
  • Shattuck, S. O. 1987. An analysis of geographic variation in the Pogonomyrmex occidentalis complex (Hymenoptera: Formicidae). Psyche (Camb.) 94: 159-179 (page 175, see also)
  • Wheeler, G. C. and J. Wheeler. 1986. The ants of Nevada. Natural History Museum of Los Angeles County, Los Angeles.