Stenamma punctatoventre

Stenamma punctatoventre
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Myrmicinae
Tribe:	Stenammini
Genus:	Stenamma
Species:	S. punctatoventre
Binomial name
Stenamma punctatoventre Snelling, R.R., 1973 Specimen labels

There is little known about the biology of this species. The type specimens were collected under a decayed limb in litter. Additional collections have been made in conifer forest, mixed forest, and riparian woodlands. Workers have typically been captured in leaf litter, under stones, or as single stray foragers.

Identification

Eyes of worker with 4-6 facets in greatest diameter and separated from mandibular insertions by 1.3-1.8 x EL; first gastric sternite and tergite both closely punctulate in part; cephalic rugulae fine, largely effaced by dense punctulation; mesopleura densely and coarsely punctate, rugulae obscure when present. Workers are medium ferruginous, but variable, usually with the cephalic dorsum being conspicuously darker and the apex of the gastric segments yellowish. (Snelling 1973)

Distribution

USA. Known from California and Washington state.

Latitudinal Distribution Pattern

Latitudinal Range: 48.73333° to 33.34°.

North Temperate	North Subtropical	Tropical	South Subtropical	South Temperate

• Source: AntMaps

Distribution based on Regional Taxon Lists

Nearctic Region: United States (type locality).

Distribution based on AntMaps

Distribution based on AntWeb specimens

Check data from AntWeb

Countries Occupied

Number of countries occupied by this species based on AntWiki Regional Taxon Lists. In general, fewer countries occupied indicates a narrower range, while more countries indicates a more widespread species.

Estimated Abundance

Relative abundance based on number of AntMaps records per species (this species within the purple bar). Fewer records (to the left) indicates a less abundant/encountered species while more records (to the right) indicates more abundant/encountered species.

Nomenclature

The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.

• punctatoventre. Stenamma punctatoventre Snelling, R.R. 1973c: 10, figs. 12, 13, 20, 21, 55 (w.q.m.) U.S.A. (California).
  • Type-material: holotype worker, 24 paratype workers, 4 paratype queens, 2 paratype males.
  • Type-locality: holotype U.S.A.: California, Placer County, Todd’s Creek, ca 5 mi. W Foresthill, ca 1900 ft, 24.vi.1962 (R.R. Snelling); paratypes: 15 workers with same data, 9 workers, 4 queens, 2 males California, Tuolumne County, Dodge Ridge, 6000 ft, 6.ix.1967, no.182 (G.C. & J.N. Wheeler).
  • Type-depositories: LACM (holotype); AMNH, DRIR, LACM, MCZC, USNM (paratypes).
  • Status as species: Smith, D.R. 1979: 1359; Wheeler, G.C. & Wheeler, J. 1986g: 34 (in key); Bolton, 1995b: 393; Ward, 2005: 67.
  • Distribution: U.S.A.

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

Description

Worker

Measurements. HL 0.70-0.83 (0.75); HW 0.56-0.67 (0.60); SL 0.46-0.55 (0.50); WL 0.80-0.94 (0.86); PW 0.36-0.46 (0.43).

Head. Head a little longer than broad, CI 77-87 (80), longer than scape, slightly narrowed toward occiput. Eyes of moderate size, with 4-6 facets in greatest diameter, OMD 1.3-1.8 (1.50) x EL; OI 12-15 (13). Scape stout, a little shorter than HW, SI 76-86 (83), cylindrical, distinctly thickened near apex. Mandible with six or seven teeth, three apical teeth largest, second basal tooth reduced; mandibles shiny, striate basally, striatopunctate apically. Median lobe of clypeus slightly produced, exceeding clypeal margin; longitudinally depressed and laterally carinulate, with transverse carinula anteriorly, so it appears truncate in frontal view. Depressed frontal area shiny; frontal lobes densely punctulate and dull; remainder of head slightly shiny, densely punctulate and with fine longitudinal rugulae, forming fine reticulae above and on sides; rugulae mostly obscured by punctulation.

Thorax. Pronotal neck moderately shiny, lightly punctulate; with transverse carinula at summit of slope; dorsally with fine longitudinal rugulae which extend onto mesonotum; interspaces moderately shiny and lightly punctulate; laterally with a few obscure, widely spaced rugulae, interspaces shiny, lightly and sparsely punctulate. Mesopleura slightly shiny, densely and coarsely punctate, a few obscure longitudinal rugulae present. Sides of propodeum densely and coarsely punctate, with more distinct longitudinal rugulae; dorsum densely punctulate and slightly shiny; spines short, sharp, separated by about twice their length.

Petiole. Dorsal face of anterior peduncle about as long as anterior face of node, node cuneate in profile; peduncle below with short blunt tooth anteriorly. Postpetiole, from above, slightly broader than long, sides nearly straight; in profile, anterior face nearly vertical; without anterior projection ventrally. Sides and venter of petiole and post-petiole dull, densely punctulate; nodes a little shinier, a little more lightly punctulate, without evident rugulae.

Gaster. First tergite slightly shiny and densely punctulate basally, punctulae becoming finer and sparser to about middle of segment, apical half shiny, but not polished. First sternite densely punctulate on basal half or more.

Pilosity. With numerous scattered erect hairs, longest on clypeus and promesonotum; those of frons mostly short, but a scattering of conspicuously longer hairs.

Color. Medium ferruginous, but variable, usually with cephalic dorsum conspicuously darker; apex of gastric segments yellowish.

Queen

Measurements. HL 0.80; HW 0.66-0.70; SL 0.53-0.57; WL 1.10-1.l3; PW 0.60-0.62; wing length 4.0-4.3.

Very similar to female of Stenamma chiricahua. Head shape similar, CI 83-88; SI 78-83. Eyes proportionately a little smaller, OMD 0.66-0.75 x EL; OI 25. Clypeal structure as in worker. Cephalic sculpture as described for worker. Pronotum more finely rugulose than in S. chiricahua, interspaces much wider. Area between mesoscutal parapsides polished, without longitudinal striae, with sparse fine piligerous punctures separated by two or more times a puncture diameter. Mesopleura less coarsely striate in upper half. Basal area of propodeum smooth, without transverse rugulae. First sternite with fine striations, at least at sides. Wing venation as in S. chiricahua.

Male

Measurements. HL 0.55-0.57 (0.55); HW 0.47-0.48 (0.48); SL 0.23; WL 1.13-1.20 (1.l3); PW 0.63; wing length 3.4.

Very similar to male of S. chiricahua but eyes smaller, OI 41-42 (42); CI 83-88 (88); SI 48-50 (48). Scutellum finely lineo-punctulate. Wings similar to those of Stenamma chiricahua.

Type Material

Holotype and 15 paratype workers: Todd's Creek, about 5 mi W. Foresthill, Placer Co., CALIF., elev. ca. 1900', 24 June 1962 (R. R. Snelling), under decayed limb in litter. Allotype male and one male, four female, nine worker paratypes: Dodge Ridge, 6000', Tuolumne Co., CALIF., 6 Sept. 1967 (G. C. and J. N. Wheeler, #182). Holotype, allotype, two female and 14 worker paratypes in LACM; one male, one female, three worker paratypes in GCW; one female, three worker paratypes in MCZ; one paratype each in AMNH, USNM, ACC, WSC.

Etymology

Morphological. Combining form of punctum (dot or point) plus venter (belly), in allusion to the punctate first sternite.

References

• Snelling, R. R. 1973c. Studies on California ants. 7. The genus Stenamma (Hymenoptera: Formicidae). Contr. Sci. (Los Angel.) 245: 1-38 (page 10, fig. 12, 13, 20, 21, 55 worker, queen, male described)

References based on Global Ant Biodiversity Informatics

• Boulton A. M., Davies K. F. and Ward P. S. 2005. Species richness, abundance, and composition of ground-dwelling ants in northern California grasslands: role of plants, soil, and grazing. Environmental Entomology 34: 96-104
• Fisher B. L. 1997. A comparison of ant assemblages (Hymenoptera, Formicidae) on serpentine and non-serpentine soils in northern California. Insectes Sociaux 44: 23-33
• Holway D.A. 1998. Effect of Argentine ant invasions on ground-dwelling arthropods in northern California riparian woodlands. Oecologia. 116: 252-258
• Snelling R. R. 1973. Studies on California ants. 7. The genus Stenamma (Hymenoptera: Formicidae). Contributions in Science (Los Angeles) 245: 1-38.
• Staubus W. J., E. S. Boyd, T. A. Adams, D. M. Spear, M. M. Dipman, W. M. Meyer III. 2015. Ant communities in native sage scrub, non-native grassland, and suburban habitats in Los Angeles County, USA: conservation implications. Journal of Insect Conservervation 19:669–680
• Ward P. S. 1987. Distribution of the introduced Argentine ant (Iridomyrmex humilis) in natural habitats of the lower Sacramento Valley and its effects on the indigenous ant fauna. Hilgardia 55: 1-16