Stictoponera crassicornis

Collected just a few times, nothing is known about this ant's biology.

Identification
Lattke (2004) - Anterior margin of clypeal lamella ending in median convex lobe; scape mostly longitudinally strigulose; occipital lamella well developed, convex at both ends. Dorsum of abdominal segment 4 smooth with scattered punctae, laterally with longitudinally oblique costae and costulae.

Also see the Nomenclature section below.

Distribution
Known from Indonesia and Malaysia.

Distribution based on Regional Taxon Lists
Indo-Australian Region: Indonesia, Malaysia.

Castes
Males are not known for this species.

Nomenclature

 * . Ectatomma (Stictoponera) binghami subsp. crassicorne Forel, 1912n: 51 (w.) INDONESIA (Sumatra).
 * Type-material: holotype worker.
 * Type-locality: Indonesia: Sumatra, Indrapura (Tritschler).
 * Type-depository: MHNG.
 * Lattke, 2004: 107 (q.).
 * Combination in Gnamptogenys: Brown, 1958g: 228;
 * combination in Stictoponera: Camacho, Franco, Branstetter, et al. 2022: 12.
 * Subspecies of binghamii: Chapman & Capco, 1951: 29.
 * Status as species: Brown, 1954h: 6; Brown, 1958g: 228; Bolton, 1995b: 209; Lattke, 2004: 106 (redescription); Camacho, Franco, Branstetter, et al. 2022: 12.
 * Senior synonym of spiralis: Lattke, 2004: 106; Camacho, Franco, Branstetter, et al. 2022: 12.
 * Distribution: Indonesia (Java, Kalimantan, Sumatra), Malaysia (Peninsula).
 * spiralis. Stictoponera spiralis Karavaiev, 1925a: 79 (w.) INDONESIA (Java).
 * Type-material: holotype worker.
 * Type-locality: Indonesia: Java, Buitenzorg (= Bogor), Botanical Garden (Karawaiew).
 * Type-depository: SIZK.
 * Combination in Gnamptogenys: Brown, 1958g: 229.
 * Status as species: Chapman & Capco, 1951: 30; Brown, 1954h: 6; Brown, 1958g: 229; Bolton, 1995b: 210.
 * Junior synonym of crassicornis: Lattke, 2004: 106; Camacho, Franco, Branstetter, et al. 2022: 12.

Brown (1954) - Forel states that the eyes are anterior to the middle of the sides of the head, which if true would separate this form from binghamii very decisively. The other characters cited, however, indicate considerable similarity, and Forel may wen have been mistaken about the eyes. The description of Stictoponera spiralis, the next species following, also claims a similar position for the eyes. Among all the series available to me, I have seen no Stictoponera specimens with the eyes in front of the middle of the sides of the head. In any case, it is very unlikely that crassicornis can be a race of S. binghamii, since the known distribution of the latter straddles the Sumatran type locality of crassicornis. Provisional specific rank is indicated for crassicornis until the type can be re-examined.

Lattke (2004) - The type of Gnamptogenys spiralis is a typical S. crassicornis and shows nothing to distinguish it as a separate species. Brown (1954b) already suspected that it was a synonym of S. crassicornis, based on the description. S. crassicornis is similar to Stictoponera binghamii in many aspects and was originally described by Forel (1912b) as a subspecies of S. binghamii. Brown (1954) elevated crassicornis to species based on the anterior position of its compound eyes in comparison with S. binghamii. Even though the eyes are a bit more forward on the head when compared with S. binghamii, the difference is not striking. The following characters of S. binghamii will separate it from S. crassicornis: more evenly convex dorsal margin of the petiolar node when seen laterally, third and fourth antennal segments about as long as wide, no extensive striae or costulae on the sides of the fourth abdominal tergite, such sculpturing, if present, limited to small patch on the anteroventral corner of the segment in lateral view. In S. binghamii the fourth abdominal tergite has evenly convex lateral margins that gradually converge with each other posteriorly when seen dorsally in full-length view. In S. crassicornis the tergite is roughly funnel shaped with the anterolateral margins abruptly converging for a short distance before gradually converging posteriorly. Stictoponera coxalis could be confused with S. crassicornis, especially some of the forms with a smooth fourth abdominal tergite, but it has more protuberant occipital lobes and no anteromedian lobe on the clypeal lamella.

Worker
Lattke (2004) - Metrics (n = 7): HL 1.38-1.52, HW 1.07-1.18, ML 0.68-0.75, SL 1.10-1.21, ED 0.19-0.23, WL 1.85-1.97 mm. CI 0.76-0.80, SI 0.99-1.06, MI 0.61-0.66, OI 0.18-0.20. Head slightly wider posterad than anterad in frontal view, lateral margins relatively straight, posterior margin broadly concave, anterior margin of clypeal lamella with median convex lobe; frons rugulose-punctate with traces of striae; clypeus longitudinally carinate. Scape mostly longitudinally strigulose; occipital lamella well developed, convex at both ends.

Lateral mesosoma mostly foveolate over smooth background; katepisternum densely foveolate; mesosomal dorsum with round foveolae on smooth background; promesonotal suture faint; longitudinal smooth area present on median promesonotum; propodeal dorsum areolate. Petiolar node with convex dorsal margin in lateral view, dorsum foveolate, subpetiolar process subquadrate in lateral view; postpetiolar dorsum punctate, punctae become more shallow and sparse posterad, posterior margin scrobiculate to strigulose; postpetiolar sternum mostly smooth with low transverse strigulae; dorsum of abdominal segment 4 smooth with scattered punctae, laterally with longitudinally oblique costae and costulae; sternum transversely rugulose. Fore coxa transversely striate in lateral view; fore tarsus opposite strigil with row of stout setae; metacoxal tooth relatively straight, not hooked. Dorsum of thorax and abdominal segments 1-4 with scattered erect to subdecumbent hairs. Coloration uniformly light brown.

Queen
Lattke (2004) - Metrics (n = 2): HL 1.43, 1.47; HW 1.11, 1.11; ML 0.70, 0.73; SL 1.11, 1.16; ED 0.26, 0.29; WL 0.18, 0.19 mm. CI 0.78, 0.75; SI 0.99, 1.04; MI 0.63, 0.66; OI 0.23, 0.26. Striae on frons more noticeable; pronotum foveolate, mesonotum longitudinally strigulose-foveolate; katepisternum foveolate or striate; propodeum densely foveolate, declivity mostly smooth.

Type Material
Lattke (2004) - Holotype worker by monotypy [Indonesia], Sumatra, Indrapura (Tritschler) [Examined].

Stictoponera spiralis Karavaiev, 1925:79. Holotype worker by monotypy: [Indonesia] Java, Buitenzorg (UASK) [Examined] syn. n.

References based on Global Ant Biodiversity Informatics

 * Brown W. L., Jr. 1954. A review of the coxalis group of the ant genus Stictoponera Mayr. Breviora 34: 1-10.
 * Brown W. L., Jr. 1958. Contributions toward a reclassification of the Formicidae. II. Tribe Ectatommini (Hymenoptera). Bulletin of the Museum of Comparative Zoology 118: 173-362.
 * Chapman, J. W., and Capco, S. R. 1951. Check list of the ants (Hymenoptera: Formicidae) of Asia. Monogr. Inst. Sci. Technol. Manila 1: 1-327
 * Chapman, J.W. and S.R. Capco. 1951. Check list of the ants (Hymenoptera: Formicidae) of Asia. Monographs of the Institute of Science and Technology (Manila) 1: 1- 327
 * Forel A. 1912. Einige neue und interessante Ameisenformen aus Sumatra etc. Zool. Jahrb. Suppl. 15: 51-78.
 * Karavaiev V. 1926. Ameisen aus dem Indo-Australischen Gebiet. Treubia 8: 413-445.
 * Karavaiev, V. 1925. Ponerinen (Fam. Formicidae) aus dem Indo-Australischen Gebiet. Konowia 4:69-81.
 * Lattke J. E. 2004. A taxonomic revision and phylogenetic analysis of the ant genus Gnamptogenys Roger in Southeast Asia and Australasia (Hymenoptera: Formicidae: Ponerinae). University of California Publications in Entomology 122: 1-266.