Lasius crinitus

Identification

 * Key to Palaearctic Lasius workers
 * Key to the Lasius of the Indian Himalayas

Distribution
Known only from the Himalayas.

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

Nomenclature

 *  crinitus. Formica crinita Smith, F. 1858b: 13 (q.) INDIA. Wilson, 1955a: 188 (w.). Combination in Lasius: Mayr, 1862: 700; in L. (Chthonolasius): Emery, 1925b: 233. Senior synonym of hingstoni: Wilson, 1955a: 187. See also: Bingham, 1903: 339; Collingwood, 1982: 293.
 * hingstoni. Acanthomyops (Chthonolasius) hingstoni Donisthorpe, 1929a: 448 (w.) INDIA. Junior synonym of crinitus: Wilson, 1955a: 187.

Worker
Wilson (1955) - On the basis of its size, pilosity, petiole shape, and geographic origin, Donisthorpe's species hingstoni is considered herein the worker caste of crinitus. Three of Donisthorpe's syntypes were used in the following diagnosis.

(1) Exceptionally large; PW 0.88, 0.90, and 0.93 mm. respectively.

(2) Dorsal crest of petiole seen in frontal view wedge-shaped, its sides tapering upward to form an angular, non-emarginate median prominence.

(3) Body pilosity consisting of long, coarse, suberect-erect hairs; maximum length on first two gastric tergites 0.18 mm., on pronotum 0.21 mm., on occiput 0.23 mm. These hairs are concentrated mainly on the occipital margin, pronotum, posterior third of the mesonotum, dorsal convexity of the propodeum, dorsal crest of the petiole, and entire gastric surface; they are occasional over the anterior surface of the head. Appendages completely lacking outstanding pilosity except for a few short, erect hairs on the coxae.

(4) Scapes somewhat flattened, maximum width at midlength 0.13 mm., minimum width 0.08 mm.

(5) Contrary to Donisthorpe's statement, the maxillary palps are not five-jointed, but six-jointed as in other species of Lasius.

Queen
Wilson (1955) - (1) Largest Lasius known; HW of Sikkim queen 1.99 mm.

(2) Pilosity of alitrunk and gaster consisting of extremely long, fine, sinuous, predominantly appressed yellow hairs, which are concentrated along the posterior margin of the pronotum, lateral faces of the scutum, lateral and ventral sides of the first two gastric segments, frontal declivity of the first gastric tergite, and whole surfaces of the exposed posterior gastric segments. They are especially abundant on the posterior gastric segments, converging to form a matted sheath over the apex, but they are sparse over most of-the dorsal surfaces of the first two gastric segments and the scutum, and absent altogether from the appendages, the head, most of the pronotum, and all of the propodeum. Similar hairs, many doubled over and wicket-shaped, form a dense fringe along the dorsal crest of the petiole. Shorter, mostly non-sinuous hairs occur on the mandibles and around the metapleural gland openings. The single specimen examined (Sikkim) is rather badly battered and probably has had some hairs worn off, but its pilosity pattern still agrees generally with that described by Bingham for the holotype.

(3) Scape moderately flattened; in the Sikkim specimen, maximum width at midlength 0.15 mm., minimum width 0.12 mm.

(4) Gastric tergites with abundant appressed pubescence.

(5) Body uniformly ochraceous, the appendages somewhat lighter. The entire body, including the gastric tergites, shagreened and feebly shining to subopaque.

(6) Petiole in frontal view with broadly rounded dorsolateral corners, converging toward the midline to meet a narrow, obtusely angular median excision.

Type Material
Wilson (1955) - HOLOTYPE. A queen in the British Museum.