Rhopalomastix javana

Wheeler (1929) - The type specimens were "collected from a sample of bark of a dying Mangifera indica, which was forwarded to our Institute at Buitenzorg by Dr. Loos, the agricultural expert at Bondowoso (Res. Besoeki, Eastern Java). Dr. Loos wrote us that the ants were burrowing in the bark of the dying tree. The bark was riddled by the insects over half the circumference of the tree and at least as high as he could reach. Numerous pupa were seen. The ants, however, were not considered to be the cause of the death of the tree." This note shows that the Rhopalomastix colonies may be very populous.

Specimens from Singapore were collected from bark of common native trees, e.g. Campnosperma auriculatum (Blume) Hook.f., in secondary forests and nature reserves which used to be abandoned plantations; specimens from Thailand were collected from bark of mango trees. Nests do not appear to occupy large expanses of tree bark (Wang, Yong & Jaitrong, 2018).

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

Nomenclature

 *  javana. Rhopalomastix rothneyi subsp. javana Wheeler, W.M. 1929d: 96, fig. 1 (w.q.m.) INDONESIA (Java).
 * Status as species: Wang, Yong & Jaitrong, 2018: 310.

Worker
Length 1.3-1.8 mm.

Averaging smaller than the typical form of the species. Head not longer than broad; thorax shorter, only 1 2/3 times as long as broad, with the epinotum distinctly narrower than the promesomotum. Median tooth of the anterior clypeal border very indistinct. Eyes smaller, consisting of only 12 to 14 facets. Sculpture finer than in the subsp. johorensis; color similar, but the head and thorax more yellowish ferruginous, the gaster clouded with brown apically.

Queen
(dealated). Length 2.5-2.8 mm.

Antennae 10-jointed as in the worker. Deep castaneous brown; pronotum, thoracic sutures, pedicel and appendages paler, more reddish brown. Sculpture as in the typical rothneyi, the anterior third of the head and the thoracic dorsum very finely longitudinally striated, the posterior portion of the head shining, sparsely and rather coarsely punctate, the gaster shining, with finer, piligerous punctures.

Male
Length 2-2.3 mm.

Black, with brown appendages. Wings clear and hyaline, with dark brown veins and pterostigma, the latter small and subelliptical. The costal vein is absent basal to the pterostigma and there is a distinct indication of a former division of the long cubital cell into two cells and pale indications of former prolongations of the cubitus and discoidal veins towards the tip of the wing. The hind wing is narrow and has only one distinct vein, the media.

Type Material
Described from numerous workers, four females and three males taken at Bondowoso, Besoeki, Eastern Java and received from Dr. L. G. K. Kalshoven. Three syntype workers on 1 pin (USNM, cotype: MCZ.6.9.20783/ SNM.595.31) were examined by Wang, Yong & Jaitrong (2018). One worker (top on pin) was selected as the lectotype.

References based on Global Ant Biodiversity Informatics

 * 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
 * Wang W. Y., G. W. J. Yong, and W. Jaitrong. 2018. The ant genus Rhopalomastix (Hymenoptera: Formicidae: Myrmicinae) in Southeast Asia, with descriptions of four new species from Singapore based on morphology and DNA barcoding. Zootaxa 4532: 301-340.
 * Wheeler W. M. 1929. The ant genus Rhopalomastix. Psyche (Cambridge) 36: 95-101.