Ectomomyrmex javanus

Distribution based on Regional Taxon Lists
Indo-Australian Region: Indonesia, Philippines. Oriental Region: Cambodia, India, Taiwan, Vietnam. Palaearctic Region: China, Japan, Republic of Korea.

Japan (Kyushu (southern part), Tsushima I., Nansei Is).

Biology
This species  nests  under  stones  at  forest margins. Workers may be found foraging individually on the ground; they do not form trails, and are able to sting painfully.

Nomenclature

 *  javana. Ectomomyrmex javanus Mayr, 1867a: 84, pl. 2, fig. 9 (w.q.) INDONESIA (Java). Ogata, 1987: 113 (m.). Combination in Pachycondyla (Ectomomyrmex): Emery, 1900d: 667; in Ectomomyrmex: Bingham, 1903: 86; Wheeler, W.M. 1921c: 530; in Pachycondyla: Brown, in Bolton, 1995b: 306; in Ectomomyrmex: Schmidt & Shattuck, 2014: 193. Senior synonym of cambodjana, denticeps, horni, japonica, maternus, sundaicus, tonkina: Yasumatsu, 1962: 94. See also: Bingham, 1903: 87.
 * sundaicus. Ectomomyrmex sundaicus Mayr, 1867a: 85 (q.) INDONESIA (Java). Junior synonym of astuta: Bingham, 1903: 86; of javana: Yasumatsu, 1962: 94.
 * maternus. Ectomomyrmex javanus r. maternus Forel, 1900d: 321 (diagnosis in key) (w.) INDIA. Forel, 1922: 90 (q.). Combination in Pachycondyla (Ectomomyrmex): Emery, 1901a: 46. Raised to species: Bingham, 1903: 87. Subspecies of javana: Emery, 1911d: 79; Wheeler, W.M. 1913e: 233; Forel, 1922: 90. Junior synonym of javana: Yasumatsu, 1962: 94.
 * japonica. Pachycondyla (Ectomomyrmex) japonica Emery, 1902c: 31 (w.) JAPAN. Teranishi, 1940: 6 (m.). Combination in Ectomomyrmex: Santschi, 1925f: 82. Junior synonym of javana: Yasumatsu, 1962: 94.
 * cambodjana. Pachycondyla (Ectomomyrmex) astuta subsp. cambodjana Forel, 1911e: 253 (w.) CAMBODIA. Junior synonym of javana: Yasumatsu, 1962: 94.
 * denticeps. Ectomomyrmex denticeps Wheeler, W.M. 1929g: 32, fig. 2 (w.) TAIWAN. Junior synonym of javana: Yasumatsu, 1962: 94.
 * tonkina. Pachycondyla (Ectomomyrmex) tonkina Santschi, 1920h: 159 (w.) VIETNAM.
 * [Also described as new by Santschi, 1924c: 96.]
 * Combination in Ectomomyrmex: Wheeler, W.M. 1927d: 1.
 * Combination in Pachycondyla: Brown, in Bolton, 1995b: 310.
 * Combination in Ectomomyrmex: Schmidt, C.A. & Shattuck, 2014: 194.
 * Status as species: Santschi, 1924c: 96; Wheeler, W.M. 1927d: 1; Wheeler, W.M. 1929f: 1; Wheeler, W.M. 1930h: 59; Chapman & Capco, 1951: 63; Bolton, 1995b: 310 (error) ; Zhou & Ran, 2010: 109 (error); Guénard & Dunn, 2012: 61 (error).
 * Junior synonym of javanus: Yasumatsu, 1962: 94; Bolton, 1995b: 306.

Worker
Wheeler (1929) for Ectomomyrmex denticeps - Length nearly 8 mm.

Head as broad as long, subrectangular, slightly narrower in front than behind, with somewhat convex sides, feebly excised posterior border and concave, truncated occipital surface, flattened towards the lateral borders which are distinctly though not sharply ridged. Each of the postero-inferior angle is produced as a distinct but rather blunt tooth. Eyes well-developed, nearly as long as their distance from the clypeus, with about 15 facets in their greatest diameter and situated at the anterior fourth of the head. Mandibles rather long and narrow, with distinctly concave external borders, the apical borders broad, with seven subequal basal and three larger apical teeth. Clypeus short but not carinate in the middle behind, somewhat depressed laterally, its anterior border sinuately emarginate in the middle. Antennal scapes curved, reaching to the posterior corners of the head; funiculus distinctly thickened apically, all its joints longer than broad, the three basal subequal, nearly 1 1/2 times as long as broad, the penultimate joints shorter. Pronotum rather convex, neither flattened nor marginate on the sides, slightly broader than long, its inferior corners rectangular but not dentate; promesonotal suture very distinct, strongly impressed; mesoepinotal suture indistinct dorsally; mesonotum and base of epinotum in profile straight and horizontal above, their sides scarcely compressed, the epinotal declivity sloping and somewhat longer than the base, crenulately marginate on the sides, the median surface distinctly concave. Petiole twice as high as long, the scale seen from behind narrowed below, broadly rounded above and with the middle of the superior border feebly angulate in the middle; the anterior surface flattened but convex in profile, with rather sharp lateral borders. Postpetiole broader than long, its anterior portion perpendicularly truncated and clearly marginate above. First gastric segment scarcely broader than the postpetiole, 1 1/2 times as broad as the petiole. Legs rather slender.

Subopaque; postpetiole and gaster more shining. Mandibles finely and regularly longitudinally striate. Clypeus obscurely punctate-rugulose. Upper surface and sides of head longitudinally rugulose, the rugules on the front regularly diverging to the posterior ends of the lateral keels. Truncated occiptal surface shining, with diverging and laterally descending rugae. Thorax longitudinally rugulose, except the upper surface of the pronotum which is transversely and arcuately rugulose. The rugules are fine on the mesonotum, coarser and sinuate on the sides of the epinotum; declivous surface of latter with sharp, regular and transversely arcuate rugre, which are concave dorsally. Anterior and posterior surfaces of petiolar scale transversely rugulose, the latter more finely than the former, with the rugules arcuate and curved upward rather strongly on the sides. Petiole and gaster very finely and superficially punctulate. Antennal scapes and legs, including the coxae, coarsely and densely reticulate-punctate, the scapes more scabrous and more opaque.

Hairs yellow, short, erect and rather coarse, very uneven, longest on the mandibles, gula and tip of abdomen, very short on the head, more numerous and conspicuous on the thoracic dorsum and petiolar border; scattered on the legs. Pubescence long, and subappressed but not very dense, finer on the appendages, poorly developed on the thorax.

Black; mandibles, borders of frontal carinae, antennae, legs and posterior borders of postpetiolar and gastric segments, dark red; median portions of scapes and femora and bases of coxae black.