Strumigenys balux

Identification
Bolton (2000) - A member of the chroa complex in the Strumigenys scotti-group. S. balux is distinguished from other species in the chroa-complex by lacking a pronotal humeral hair, having a single pair of clavate hairs on the anterior margin of the mesonotum, and having mandibular lamellae more or less touching at full closure. See under Strumigenys cabira for further discussion.

Distribution based on Regional Taxon Lists
Malagasy Region: Madagascar.

Nomenclature

 *  balux. Strumigenys balux Fisher, in Bolton, 2000: 672 (w.) MADAGASCAR.

Worker
Holotype. TL 2.5, HL 0.62, HW 0.47, CI 77, ML 0.32, MI 51, SL 0.40, SI 85, PW 0.29, AL 0.69. Characters of chroa-complex. Mandibles almost straight and at full closure parallel except near base. Ventral surface of apicoventral fork tooth with 1 or 2 basally located denticles. A narrow lamella present on inner margin of mandible from base to proximal preapical tooth; in full-face view inner margins of lamellae shallowly and evenly convex and more or less touching at full closure. Upper scrobe margin rounding into the sides of head near posterior margin of eye. Eye large, the maximum diameter distinctly greater than the maximum width of the scape. Hairs on leading edge of scape slender, slightly flattened or spoon-shaped apically. Cephalic dorsum with curved narrow spatulate to spoon-shaped ground-pilosity, the upper scrobe margins fringed with a row of hairs which are the same shape and size as those on the dorsum. Cephalic dorsum with 4 simple standing hairs arranged in a transverse row close to the occipital margin. Pronotal humeral hair absent. Anterior margin of mesonotum with a pair of erect clavate hairs. Ground-pilosity on alitrunk as on head. Posterior portion of mesonotum shallowly concave dorsally; propodeal dorsum sloping gradually to declivity. Propodeal teeth slender and acute; lamella on declivity narrow. Head, alitrunk dorsum and sides, petiole, and postpetiole disc in dorsal view reticulate-punctate. Ventral spongiform tissue on petiole moderately developed, lateral lobes small and vestigial. Postpetiole with distinct lateral and ventral spongiform lobes. Base of first gastral tergite with a continuous row of costulae. Dorsal surfaces of petiole, postpetiole and gaster with stout standing hairs which are thickened apically. Colour dull yellowish brown.

Measurements of non-paratypic material: TL 2.3-2.5, HL 0.57-0.61, HW 0.45-0.50, CI 77-82, ML 0.29-0.30, MI 49-51, SL 0.36-0.40, SI 75-86, PW 0.27-0.29, AL 0.62-0.67 (4 measured).

Type Material
Holotype worker, Madagascar: 45 km. S Ambalavao, 22°13'S, 47°I'E, 785 m., 25.ix.1993, sifted litter (leaf mold, rotten wood) rainforest #696 (26)-10 (B. L. Fisher).