Strumigenys ipsea

Identification
Bolton (2000) - S. ipsea is the only member of the chroa-complex that lacks a mandibular lamella, but is still easily recognized as belonging to this complex by the more or less straight mandibles. S. ipsea is distingui shed from other species in the chroa-complex by having the mesopleural gland set in a broad concave impression that extends along half of the anterior margin of the katepisternum and its large size, HL 0.79-0.83, HW 0.54-0.57. In addition, the following characters help identify this species: pronotal humeral hair flagellate or looped; mesonotum with only a single pair of erect hairs; spongiform appendages of petiole nearly absent.

Distribution based on Regional Taxon Lists
Malagasy Region: Madagascar.

Nomenclature

 *  ipsea. Strumigenys ipsea Fisher, in Bolton, 2000: 685 (w.) MADAGASCAR.

Worker
Holotype. TL 3.4, HL 0.80, HW 0.52, CI 65, ML 0.44, MI SS, SL 0.58, SI 111, PW 0.31, AL 0.86. Characters of chroa-complex. Mandibles almost straight and at full closure parallel except at base; proximal preapical tooth slightly longer than the distal. Upper scrobe margin evenly and shallowly convex in full-face view, not bordered by a rim or flange, the eyes visible. Maximum diameter of eye distinctly greater than maximum width of scape, with 5-6 ommatidia in longest row. Scape long and slender, subcylindrical and only very feebly curved near the base; hairs on leading edge small and slender, slightly flattened or spoon-shaped apically. Cephalic dorsum clothed with curved narrow spatulate to spoon-shaped ground-pilosity, concentrated on anterior half of head; the upper scrobe margins fringed with a dense row of hairs which are the same shape and size as those on the dorsum. Cephalic dorsum with 6 simple standing hairs arranged in a transverse row of 4 close to the occipital margin and a more anteriorly situated pair. Pronotal humeral hair flagellate. Mesonotum with a single pair of standing hairs. Propodeum with one pair of short, posteriorly curved hairs immediately anterior of propodeal spines. Ground-pilosity on alitrunk as on head but the hairs smaller and sparser. Promesonotum convex; posterior portion of mesonotum shallowly depressed behind the level of the standing hairs. Anterior mesonotum with a narrow carina above the mesothoracic spiracle. Mesopleural gland set in a broad concave impression extending along half of the anterior margin of the katepistemum; in profile, maximum width of concave impression approximately equal to width of fore coxa. Propodeal tooth triangular, lamellate, pointed apically; lamella absent from declivity. Dorsal alitrunk reticulate-punctate. Sides of alitrunk superficially punctulate peripherally, the pleurae mostly smooth. Petiole node at least as long as broad, often longer than broad. Postpetiole disc mostly smooth, lateral margins longitudinally striolate and feebly punctate. Spongiform appendages of petiole nearly absent, with only a very narrow superficial ventral strip. Postpetiole with small ventral spongiform lobes. Basigastral costulae sparse and short. Dorsal surfaces of petiole, postpetiole and gaster with standing hairs which are simple or very slightly thickened apically. Colour yellowish brown to medium brown.

Paratypes. TL 3.4-3.5, HL 0.79-0.83, HW 0.54-0.57, CI 66-72, ML 0.42-0.43, MI 52-54, SL 0.57-0.62, SI 99-112, PW 0.34-0.37, AL 0.88-0.93 (5 measured). As holotype.

Type Material
Holotype worker, Madagascar: Provo Diego Suarez, Marojejy Mts, 29.xi.1972, 2060 m., dense forest #4052 (J. -M. Betsch).

Paratypes. 5 workers with same data as holotype.