Strumigenys bibiolona

Known from forest habitats that vary from wet to dry, the dozens of collection records indicate this is a species nests in dead wood (rotten log, rotten branch, dead twig above ground).

Identification
Bolton (2000) - A member of the chilo complex in the Strumigenys grandidieri-group. S. bibiolona forms a close species pair with Strumigenys chilo within the grandidieri-group, but bibiolona is known only from collections from the humid forest in the northwest of Madagascar, while chilo is found throughout the eastern rainforest. Similarities of the two species are discussed under chilo. S. bibiolona is easily differentiated from chilo by the following characters:

1 Dorsum of head evenly and gradually curved from middorsum to posterior margin of occipital corner; in profile, outline of dorsal margin of occipital corners curved, not flat.

2 Propodeal spines long, much longer than distance between base of spines.

Distribution based on Regional Taxon Lists
Malagasy Region: Madagascar.

Nomenclature

 *  bibiolona. Strumigenys bibiolona Fisher, in Bolton, 2000: 650 (w.q.) MADAGASCAR.

Worker
Holotype. TL 3.5, HL 0.85, HW 0.52, CI 61, ML 0.51, MI 60, SL 0.65, SI 126, PW 0.32, AL 0.91. Characters of chilo-complex. Mandibles almost straight and at full closure parallel. Apical fork of mandible subtended by a third, shorter spiniform tooth; the fork effectively 3-dentate; without intercalary teeth or denticles. Preapical teeth absent. Upper scrobe margin ends anterior of preocular groove; when viewed in profile, upper scrobe margin curves downwards at anterior margin of vertical preocular groove of side of head and almost meets preocular lamina; scrobe margin does not extend across dorsal apex of preocular groove so that the latter extends uninterrupted to the cephalic dorsum. Eye large, convex, and plainly visible in full-face view. Dorsum of head evenly and gradually curved from middorsum to posterior margin of occipital corner; in profile, outline of dorsal margin of occipital corners curved. Scape long and slender, approximately straight, the leading edge with a row of slender hairs which are slightly flattened or spoon-shaped apically. Cephalic dorsum with inconspicuous curved fine ground-pilosity; the upper scrobe margin without a row of hairs. Cephalic dorsum with 4 simple standing hairs arranged in a transverse row close to the occipital margin. Dorsum of head reticulate-punctate. Alitrunk dorsum without standing hairs. Propodeum without a pair of short posteriorly curved hairs i m mediately anterior of propodeal spines. Ground-pilosity on alitrunk as on head but sparser. With the alitrunk in profile the posterior portion of the mesonotum sharply depressed, the metanotal groove represented by a shallow impression. Pronotal humeri rounded. Lateral margin of posterior pronotum bluntly marginate. Anterior mesonotum without a narrow carina above the mesothoracic spiracle. Propodeal spines slender, almost spiniform; spines long, much longer than distance between base of spines; propodeal lamella absent. Alitrunk dorsum and sides reticulate-punctate. Petiole node in dorsal view reticulate-punctate and much longer than broad. Postpetiole reticulate-punctate. Waist segments without spongiform appendages. Disc of postpetiole with spongiform collar. Basigastral costulae absent. First gastral tergite and sternite with superficial reticulate-punctate sculpture over the anterior half or less of the sclerite, remainder of gaster smooth and shiny. Petiole without erect hairs. Dorsal surface of postpetiole with a pair posteriorly projecting stout hairs; gaster with stout standing hairs which are weakly swollen apically. Colour dull yellow to light brown.

Paratypes. TL 3.3-3.5, HL 0.80-0.85, HW 0.48-0.54, CI 60-64, ML 0.49-0.52, MI 60-64, SL 0.63-0.67, SI 117-132, PW 0.30-0.34 AL 0.87-0.93 (4 easured). As holotype.

Measurements of this material extend the range shown by the type-series: HL 0.85-0.97, HW 0.52-0.59, CI 58-66, ML 0.53-0.59, MI 61-64, SL 0.66-0.74, SI 115-131 (5 measured).

Type Material
Holotype worker, Madagascar: Provo Antsiranana, R.S. Manongarivo, 10.8 km. 229° SW Antanambao, 400 m., 13°57.7'S, 48°26.0'E, 8.xi.1998, sifted litter (leaf mold, rotten wood). rainforest #1996 (37)-3 (B. L. Fisher).

Paratypes. 22 workers and 3 queens (dealate) with same data as holotype but coded (2)-4, (21)-4, (27)-2, (28)-4, (29)-2, (30)-5, (31)-1, (31)-2, (34)-2, (38)-4, (40)-4, (41)-2, (42)-3, (44)-2, (46)-5, (54)-3, (54)-5, (57)-2, (60)-3, (64)-1, (64)-2, (65)-1, (68)-3, (74)-2.

References based on Global Ant Biodiversity Informatics

 * Bolton, B. 2000. The Ant Tribe Dacetini. Memoirs of the American Entomological Institute 65
 * Fisher B. L. 2003. Formicidae, ants. Pp. 811-819 in: Goodman, S. M.; Benstead, J. P. (eds.) 2003. The natural history of Madagascar. Chicago: University of Chicago Press, xxi + 1709 pp.
 * Fisher, B. 2002. Ant diversity patterns along an elevational gradient in the Reserve Speciale de Manongarivo, Madagascar. in Gautier, L. and S.M. Goodman, editors, Inventaire Florestique et Faunistique de la Reserve Speciale de Manongarivo (NW Madagascar)