Parasyscia luteoviger

The types were collected from downed wood in a forest.

Identification
Brown (1975) - This species is a member of the dohertyi group of the Indo-Melanesian area. Its closest relatives are 2-3 undescribed species from this general area, but it differs from all of these in details of head shape and sculpture, in the shape of the petiolar node apex, and in the color pattern; the yellow ovoidal apical segment of the antenna is characteristic and gives the ant its name.

Distribution based on Regional Taxon Lists
Oriental Region: Sri Lanka.

Nomenclature

 *  luteoviger. Cerapachys luteoviger Brown, 1975: 70, figs. 54-57, 90, 91, 93 (w.q.) SRI LANKA.
 * Combination in Parasyscia: Borowiec, M.L. 2016: 205.
 * Status as species: Bolton, 1995b: 143.

Worker
Holotype: TL 4.0, HL 0.82, HW 0.67 (CI 82), ML 0.10, scape L 0.53, greatest diameter of eye 0.20, WL 1.06, petiolar node L 0.37, W 0.49, postpetiole L 0.46, W 0.62 mm.

Paratypes (9 from type colony): TL 3.9-4.0, HL 0.80-0.81, HW 0.65-0.68 (CI 81-84), ML 0.09-0.10, scape L 0.46-0.51, greatest diameter of eye 0.18-0.20, WL 1.01-1.04, petiolar node L 0.36-0.38, W 0.44-0.48, postpetiole L 0.42-0.46, W 0.57-0.60 mm.

Posterior border straight to feebly convex when head is viewed full face. Median carina or tubercle of clypeus not well developed, not toothlike seen in full-face view. Trunk short and high, evenly convex above, parallel-sided, with transverse pronotal carina complete and forming subrectangular humeri as seen from above. Declivity of propodeum with carinate lateral margins, incomplete above in the middle.

Petiolar node distinctive in shape; anterodorsal border concavely marginate. The body is smooth and shining, with spaced piligerous punctures, except for petiole and base of first gastric tergum, which are more crowded with coarse punctures or foveolae, and postpetiole, which is densely covered with coarse and fine continguous to subcontiguous piligerous punctures and very abundant longer and shorter decumbent hairs, consequently, its general surface only weakly shining. Posterior half of gaster smooth and shining, with only scattered, fine punctures. Propodeal declivity and anterior face of petiolar node smooth, shining, densely punctulate, and with a very fine appressed pubescence. Antennae and legs with moderate decumbent pubescence and some longer decumbent hairs (longer erect hairs also on scapes). Longer erect and suberect hairs of body moderately abundant, more abundant on postpetiole and gaster. Pygidium densely punctate, with a smooth, shining median strip; spinules in a single row on each side of apex.

Inner genual plate of hind coxae sharp and forming a crescentic margin, but not expanded as a lobe.

Color light ferruginous red, with posterior sides of trunk darker, more brownish. Apical segment of antenna light yellow, contrasting with the red of the rest of the body and appendages.

Queen
Ergatoid: TL 4.5, HL 0.87, HW 0.73, (CI 84), ML 0.08, scape L 0.55, greatest diameter of eye 0.19, WL 1.21, petiolar node L 0.45, W 0.54, postpetiole L 0.52, W 0.78 mm.

Though this individual is very like the accompanying workers except in its notably larger size and bulkier body (especially the gaster), even Wilson, the original collector, noted that in life it seemed to be the “ergatoid queen.” I can find no distinct ocelli, though ocellar pits would be difficult to distinguish from the punctate sculpture. There is a distinct indentation on the mid-vertex, about where an anterior median ocellus would normally be found. The sculpture is perhaps a little more distinct than in the workers, and the petiolar summit is at least as sharply rounded as in the worker. The hairs of the pilosity are fine and tend to be more sharply erect than in the worker. Color as in worker.

Type Material
Holotype taken from a small colony with the ergatoid queen from a piece of “Passalus-stage” rotten wood lying on the ground in forest at Gilimale, 16-20 km NE of Ratnapura, Sri Lanka (Ceylon), 18-21 July 1955, E. O. Wilson No. 1326. Wilson noted that the ants were very “nervous and active” in life. Paratypes in MCZ, BMNH-London, MHN-Geneva, and ANIC-Canberra.

References based on Global Ant Biodiversity Informatics

 * Brown W. L., Jr. 1975. Contributions toward a reclassification of the Formicidae. V. Ponerinae, tribes Platythyreini, Cerapachyini, Cylindromyrmecini, Acanthostichini, and Aenictogitini. Search Agric. (Ithaca N. Y.) 5(1): 1-115.
 * Dias R. K. S. 2006. Current taxonomic status of ants (Hymenoptera: Formicidae) in Sri Lanka. The Fauna of Sri Lanka: 43-52. Bambaradeniya, C.N.B. (Editor), 2006. Fauna of Sri Lanka: Status of Taxonomy, Research and Conservation. The World Conservation Union, Colombo, Sri Lanka & Government of Sri Lanka. viii + 308pp.
 * Dias R. K. S., K. R. K. A. Kosgamage, and H. A. W. S. Peiris. 2012. The Taxonomy and Conservation Status of Ants (Order: Hymenoptera, Family: Formicidae) in Sri Lanka. In: The National Red List 2012 of Sri Lanka; Conservation Status of the Fauna and Flora. Weerakoon, D.K. & S. Wijesundara Eds., Ministry of Environment, Colombo, Sri Lanka. p11-19.
 * Gunawardene N. R., J. D. Majer, and J. P. Edirisinghe. 2012. Correlates of ant 5Hymenoptera: Formicidae) and tree species diversity in Sri Lanka. Myrmecological News 17: 81-90.