Stigmatomma bellii

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

Nomenclature

 *  bellii. Amblyopone (Stigmatomma) bellii Forel, 1900c: 55 (w.) INDIA. Combination in Stigmatomma: Bingham, 1903: 38; in Amblyopone: Brown, 1960a: 193; in Stigmatomma: Yoshimura & Fisher, 2012: 19.

Description
Brown (1960) - I have been able to examine and compare directly the types of Stigmatomma rothneyi and bellii, and I find them to differ scarcely at all. Forel's description of bellii is in error on several crucial points. First of all, the bellii types have denticulae on the anterior clypeal margin that are approximately as distinct as in the rothneyi type, and similar in form. The eyes of the rothneyi type are slightly larger (0.22 mm. greatest diam.) than in bellii (0.18 mm. greatest diam.), but not nearly so much so as Forel claims. I count about 70-90 facets in the rothneyi type before me (here designated and labeled as lectotype); though the count is very difficult, I find the two bellii syntypes to have almost as many facets (50-70) as rothneyi. In fact, under the best circumstances of counting, I seriously doubt whether the difference is significant.

The bellii types are slightly more coarsely and quite opaquely sculptured over head, alitrunk, petiole and postpetiole; in the rothneyi type, these areas are very densely punctate and nearly opaque, but many of the punctures do have narrow shining spaces between them, and the postpetiole is more definitely shining. Both of these species have the anterior genal angles bluntly subrectangular, and not projecting. The palpal count for both of the bellii syntypes is maxillary 4; labial 3 (not 2 and 3, as Forel states); the palpi cannot be seen in the rothneyi type. These two species may well be geographical variants; bellii is from Kanara, on the western side of the Peninsula south of Bombay, while rothneyi is from Barraekpore, near Calcutta. From Poona, central Madras Presidency, and Orissa, all on the Indian Peninsula, I have numbers of large males that probably belong to bellii and/or rothneyi. These males have distinctive genitalia and a long, narrow caudal process on the subgenital plate. The whole terminalia most resemble those of a series of large males of another species from Formosa, probably the same as the male doubtfully attributed to bruoii by Forel (1913, Arch. Naturg., 79 (A6):183), but which is more likely a member of the reclinata group.

References based on Global Ant Biodiversity Informatics

 * Basu P. 1994. Ecology of ground foraging ants in a tropical evergreen forest in Western Ghats, India. PhD Thesis, School of ecology and environmental sciences, Pondichery University, India. 155 pages.
 * Basu P. 1997. Seasonal and spatial patterns in ground foraging ants in a rain forest in the Western Ghats, India. Biotropica 29(4): 489-500.
 * Forel A. 1900. Les Formicides de l'Empire des Indes et de Ceylan. Part VI. J. Bombay Nat. Hist. Soc. 13: 52-65.