Stereomyrmex dispar

AntWiki: The Ants --- Online
Stereomyrmex dispar
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Crematogastrini
Genus: Stereomyrmex
Species: S. dispar
Binomial name
Stereomyrmex dispar
(Wheeler, W.M., 1934)

Stereomyrmex dispar castype05026 profile 1.jpg

Stereomyrmex dispar castype05026 dorsal 1.jpg

Specimen labels

Stereomyrmex dispar was described from a unique worker taken in 1933 on remote Bellona Island (11°20’S; 159°47’E), south of Guadalcanal, Solomon Islands (Wheeler, 1934).

Identification

Distribution

Latitudinal Distribution Pattern

Latitudinal Range: -9.466666667° to -11.33333333°.

 
North
Temperate
North
Subtropical
Tropical South
Subtropical
South
Temperate

Distribution based on Regional Taxon Lists

Indo-Australian Region: Solomon Islands (type locality).

Distribution based on AntMaps

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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.
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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.
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Biology

Castes

Images from AntWeb

Stereomyrmex dispar castype05026 profile 2.jpgStereomyrmex dispar castype05026 dorsal 2.jpg
Holotype of Willowsiella disparWorker. Specimen code castype05026. Photographer April Nobile, uploaded by California Academy of Sciences. Owned by CAS, San Francisco, CA, USA.

Nomenclature

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

  • dispar. Willowsiella dispar Wheeler, W.M. 1934a: 175, fig. 1 (w.) SOLOMON IS (Bellona I.).
    • Type-material: holotype worker.
    • Type-locality: Solomon Is: NW end Bellona I., 23.vi.1933, Templeton Crocker Expd. (M. Willows).
    • Type-depository: CASC.
    • Combination in Stereomyrmex: Bolton, 2003: 273.
    • Status as species: Wheeler, W.M. 1935g: 27; Wilson, 1962c: 22; Taylor, 1976a: 83; Taylor, 1991a: 284; Bolton, 1995b: 424; Bolton, 2003: 273; Sarnat, et al. 2013: 72.
    • Distribution: Solomon Is.

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

Description

Worker

Length very nearly 2.5 mm.

Head trapezoidal, slightly longer than broad, with nearly straight, anteriorly converging sides and feebly and evenly convex posterior border; in profile moderately convex above and subtruncate behind, with concave occipital border. Eyes slightly in front of the middle of the sides, moderately large, convex, semicircular, with straight inferior orbit. Mandibles with straight external borders and two or three blunt teeth in addition to the acute apical tooth. Antennal scapes reaching to the posterior fourth of the head, curved at their bases; first funicular joint one and one-half times as long as broad; joints 2-7 fully twice as broad as long; eighth nearly as long as the three preceding joints• together; the ninth as long as broad, the terminal distinctly longer than the combined eighth and ninth. Thorax in profile convex and evenly rounded above; seen from above slightly more than twice as long as broad, broader in front than behind, with broadly arcuate anterior border, subrectangular humeri and straight sides which gradually converge posteriorly to the epinotal region where they become subparallel. Epinotal spines as broad at the base as long, acute, strongly compressed, subparallel, directed backward and slightly upward, the space between them sloping and feebly concave. Petiolar node in profile higher than long, truncated anteriorly and posteriorly and rounded dorsally; seen from above transversely subelliptical, broader than the epinotum, with very bluntly angulate sides, nearly one and one-half times as broad as long. The peduncle bears on each side a blunt rectangular projection and at its anteroventral border a blunt tooth. Postpetiole anteroposteriorly compressed and cuneate in profile, with straight anterior and posterior surfaces and blunt superior border; from above much narrower than the petiolar node, broadly trapezoidal, fully twice as broad as long, its anterior and lateral borders straight, the latter strongly converging posteriorly. First gastric segment subquadrate, with broadly rounded anterior and posterior corners and deeply excised anterior border.

Shining; body and legs regularly, very finely and delicately reticulate, with sparse umbilicate punctures, distinctly coarser on the mandibles, head, thorax and petiole than on the postpetiole and gaster, which are smoother and more minutely and sparsely punctate. Frontal carinae and clypeus granular, the raised median portion of the latter with a few longitudinal rugae on each side. Cheeks coarsely reticulate-rugose; lower portion of epinotal declivity with several transverse rugae.

Hairs yellowish, very short, erect only on the clypeus and tip of the gaster, elsewhere appressed and arising from the umbilicate punctures. Pubescence short, even, appressed, confined to the antennae and legs.

Black; mandibles, antennae, legs and terminal segments of gaster yellowish brown; femora dark brown, except at their bases and tips; median portion of antennal scapes somewhat infuscated.

Taylor (1991) - TL ca. 3.2; HL 0.79; HW (across eyes) 0.72, (maximum behind eyes) 0.69; CI 87; SL 0.53; SI 77; PW 0.59; WL 1.00; midline length of petiolar node 0.38; petiolar node width 0.52; midline length of postpetiole 0.24; postpetiole width 0.43.

Type Material

Described from a single specimen taken by Mr. Maurice Willows Jr. at the northwestern end of Bellona Island, Solomons (VI.23.33).

Taylor (1991) - The holotype (California Academy of Sciences, San Francisco) is mounted on 2 points, one with the head, mesosoma and petiole, the other with the postpetiole and gaster. It carries a small red tag with the words “HOLOTYPE” (printed) and “W. dispar”(hand-written); a large label reading “Willowsiella dispar Wheeler (Type)” in Wheeler’s handwriting; and four small printed white data labels, reading respectively: “Solomon Islands”; “NW end of Bellona Isd, VI 23-33”; “M. Willows Jr. Collector”; and “Templeton Crocker Exped. 1933”.

References

References based on Global Ant Biodiversity Informatics

  • Taylor R. W. 1976. The ants of Rennell and Bellona Islands. Natural History of Rennell Island, British Solomon Islands 7: 73-90.
  • Taylor, R. W. 1991. Notes on the ant genera Romblonella and Willowsiella, with comments on their affinities, and the first descriptions of Australian species (Hymenoptera: Formicidae: Myrmicinae). Psyche (Cambridge) 97: 281-296.
  • Wheeler W.M. 1934. Formicidae of the Templeton Crocker expedition, 1933. Proceedings of the California Academy of Sciences 21(14): 173-181.
  • Wheeler W.M. 1935. Check list of the ants of Oceania. Occasional Papers of the Bernice Pauahi Bishop Museum 11(11):1-56.
  • Wheeler, William Morton. 1934. Formicidae of the Templeton Crocker Expedition, 1933. California Academy of Sciences. 21(14):173-181.
  • Wheeler, William Morton.1935.Checklist of the Ants of Oceania.Occasional Papers 11(11): 3-56
  • Wilson, Edward O. 1959. The Ants of Rennell and Bellona Islands. Nat. Hist. Rennell Isl. By Solomon Isl. 4:13-23.