Strumigenys hemichlaena

This species is apparently widespread in mid-mountain altitudes (900-1900 m) in New Guinea, where it replaces Strumigenys szalayi. Collections have been made from downed branches, sticks, and rotten logs.

Identification
Bolton (2000) - A member of the Strumigenys szalayi-group. Specimens of hemichlaena are like those of populations of Strumigenys szalayi in which the gaster is distinctly darker than the head and alitrunk, except for the fact that in hemichlaena the pronotum and anterior mesonotum are also darkly coloured (alitrunk is unicoloured in szalayi). The validity of this character is weakened by the presence in LACM of two workers collected by Roy Snelling at Lakekamu Basin, Papua New Guinea, in which the pronotum and anterior mesonotum are only very slightly darker than the remainder of the alitrunk. Whether these represent intermediates or are teneral forms of hemichlaena remains undecided. Nevertheless, the suspicion arises that hemichlaena may merely be another colour-morph of szalayi (see note under Strumigenys tigris); only the acquisition of more material can resolve the problem.

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

Nomenclature

 *  hemichlaena. Strumigenys hemichlaena Brown, 1971c: 78 (w.) NEW GUINEA. See also: Bolton, 2000: 904.

Worker
Bolton (2000) - TL 3.2-3.5, HL 0.76-0.90, HW 0.52-0.64, CI 68-71, ML 0.40-0.46, MI 48-53, SL 0.50-0.58, SI 91-97, PW 0.32-0.36, AL 0.86-0.94 (4 measured). As szalayi but with different colour pattern. Head yellow to yellowish brown; pronotum and anterior mesonotum black or blackish brown; posterior mesonotum, propodeum and waist segments same shade as head; gaster glossy dark brown.

Queen
Dealate (from type nest series): TL 3.75, HL 0.88, ML 0.43, WL 0.95 mm.; CI 72, MI 49.

Eves very large, their anterior borders narrowly rounded and overhanging th deep narrow preocular groove. Mesonotum with a weak anterior median sulcus; posterior half with about 8 separated, continuous and slightly vermiculate longitudinal rugulae. Scutellum convex, with a median carinula; mesonotal ground sculpture the usual dense punctulation. Propodeal teeth stouter than in worker. Petiolar node as broad as long. Anterior corner of anepisternum, most of katepisternum, and procoxae smooth and shining. Mesonotum with a few fine erect hairs like those of head and gaster.

Ground color ferruginous yellow; dorsum of head, except occipital lobes, slightly infuscated; pronotum (not cervix) and mesonotum entirely deep ferruginous-black, metanotum deep ferruginous; gaster dark castaneous. Deposited with holotype.

Immature
Pupae with mandilbes open to more than 180 as figured by Emery for szalayi. (see above) Larvae described as “Strumigenys sp. (szalayi group)” by G. C. and J. Wheeler, 1960. Proc. Ent. Soc. Wash., 62: 27.

Type Material
Holotype worker (Zoological Museum, Bogor. lndonesia) from a type nest series of 45 workers and a single queen. Baliem River, Netherlands New Guinea. 1600 m. in rotten branch. 14 Dec., 1938, L. J. Toxopeus. For particulars concerning type locality see Toxopeus, 1940. Treubia, 17: 273-274, 278-279, or Archbold, Rand and Brass, 1942, Bull. Amer. Mus. Nat. Hist., 79: 246-250.

Bolton (2000) - Holotype worker, paratype workers and queen, INDONESIA: Irian Jaya, Baliem River, 1600 m., 14.xii.1938, in rotten branch (L. J. Toxopeus) (BZB,, , ) [examined].