Crematogaster brunnea nilgirica

Identification
Crematogaster brunnea is a complex species group consisting of six species. General characters are reddish brown colouration, head smooth and shining with faint striations near base of antennae and gena, head wider than the mesosoma, the vertex slightly emarginated; mesosoma in lateral view finely striated longitudinally, metanotum deeply concave with acute spine; petiole heart shaped, flattened above; postpetiole globose and biturberculate dorsally; gaster smooth and shining.

Crematogaster contemta (often as Crematogaster brunnea contemta) is a light bicoloured yellowish subspecies with darker brown gaster, propodeal spines small sharply pointed, thick at the base, directed downward.

Crematogaster brunnea nicevillei is a darker subspecies with smaller spines, deep metanotal groove, raised mesonotum and faintly striate gena.

Crematogaster brunnea nilgirica is restricted to southern India with prominent striations on head and mesosomal dorsum, propodeal spines large, diverging, fronto clypeal sulcus more or less pointed.

Crematogaster brunnea rabula is a dull brownish coloured subspecies with pronotum and propodeum dorsally feebly striate, propodeal spines short, pointed, thick at base diverging outwards.

Crematogaster brunnea ruginota is a light yellowish brown coloured subspecies with deep metanotal groove, strongly raised pro- and mesonotum, propodeal declivity truncate, propodeal spines smaller, pointed, thick at base, directed upward. (Akbar et al., 2023)

Distribution based on Regional Taxon Lists
Oriental Region: India.

Nomenclature

 * . Crematogaster (Acrocoelia) brunnea var. nilgirica Emery, 1922e: 149.
 * Type-material: syntype workers (number not stated).
 * Type-localities: India: Utakamand Nilgiris (Wroughton), India: Coonoor (Wroughton).
 * Type-depository: MHNG.
 * [First available use of Crematogaster subnuda r. rabula var. nilgirica Forel, 1902c: 208 (w.) INDIA (Tamil Nadu); unavailable (infrasubspecific) name.]
 * Subspecies of brunnea: Chapman & Capco, 1951: 87; Bolton, 1995b: 158; Tiwari, 1999: 47; Bharti, Guénard, et al. 2016: 36.
 * Distribution: India.