Strumigenys glycon Fisher, 2000

Bolton, B., 2000, The ant tribe Dacetini. With a revision of the Strumigenys species of the Malgasy Region by Brian L. Fisher, and a revision of the Austral epopostrumiform genera by Steven O. Shattuck., Memoirs of the American Entomological Institute 65, pp. 1-1028 : 682-683

Strumigenys glycon Fisher sp. n.

HOLOTYPE WORKER. TL 1.9, HL 0.45, HW 0.34, CI 75, ML 0.22, MI 48, SL 0.28, SI 83, PW 0.23, AL 0.48. Characters of scotti-complex. Mandibles in full-face view evenly bowed outwards, the width approximately constant from the level of the proximal preapical tooth to near the base. Upper scrobe margin evenly and shallowly convex in fullface view, not bordered by a rim or flange except immediately behind the frontal lobes, the eyes visible, the apices of the upper scrobe margins confluent with the sides of the occipital lobes through an even curve, without an angle separating the two. Eye small, maximum diameter slightly less than maximum width of scape, with 3 - 4 ommatidia in longest row. Scape narrow and subcylindrical, curved near the base, leading edge slightly expanded behind curve; hairs on leading edge filiform to narrowly spatulate. Cephalic dorsum clothed with inconspicuous narrow filiform ground-pilosity, the upper scrobe margin fringed with hairs which are similar in shape and size as those on the leading edge of the scape. Cephalic dorsum with 6 standing narrow filiform hairs arranged in a transverse row of 4 close to the occipital margin and a more anteriorly situated pair. Pronotal humeral hair fine and flagellate; central pronotum with a pair of fine, short hairs that are curved towards the midline; humeral angles rounded, lateral margin of posterior pronotum bluntly marginate. Anterior margin of mesonotum with a pair of standing filiform hairs that are thickened apically, lateral margins of mesonotum posterior of the standing hairs with shorter decumbent hairs that curve toward the midline. Propodeum with one pair of short, fine, posteriorly curved hairs immediately anterior of propodeal spines. Dorsal alitrunk with sparse inconspicuous fine appressed ground-pilosity. Dorsum of alitrunk in outline convex anteriorly and posteriorly gently sloping to the declivity. Anterior mesonotum with a thin carina above the mesothoracic spiracle; mesopleural gland set in a small circular notch. Propodeal tooth small, triangular, lamellate, pointed apically, and subtended by an inconspicuous very narrow lamella. Pronotal dorsum and sides longitudinally striolate with a longitudinal carina along dorsal midline. Mesonotal dorsum rugose with punctulate sculpture. Propodeal dorsum shiny and superficially areolate. Pleurae and sides of propodeum glassy smooth except for punctures along the vertical groove above mesopleural gland. Postpetiole disc smooth and shiny. Spongiform appendages of pedicel segments greatly expanded; in profile ventral spongiform curtain of petiolar peduncle well developed, its deepest point at least equal to height of base of peduncle. Basigastral costulae sharply defined, radiating on each side of a broad central clear area. Dorsal surface of petiole, postpetiole and gaster with standing filiform hairs. Colour light brown.

PARATYPE WORKERS. TL 1.9 - 2.0, HL 0.42 - 0.46, HW 0.34 - 0.35, CI 74 - 80, ML 0.22 - 0.23, MI 48 - 55, SL 0.27 - 0.29, SI 77 - 83, PW 0.21 - 0.22, AL 0.47 - 0.49. (4 measured). As holotype.

Holotype worker, Madagascar: 6.9 km. NE Ambanizana, 15 ° 34 ' S, 50 ° 00 ' E, 825 m., 2. xii. 1993, sifted litter (leaf mold, rotten wood), rainforest, # 976 (48) - 16 (B. L. Fisher) (MCZ).

Paratypes. 4 workers and 1 ergatogyne with same data as holotype but coded (15) - 12, (28) - 14, (45) - 14, (46) - 15, (49) - 13 (BMNH, SAM).

NON-PARATYPIC MATERIAL EXAMINED. Madagascar: R. S. Manongarivo, 14.5 km. 220 ° SW Antanambao, 1175 m. (B. L. Fisher); R. S. Manongarivo, 17.3 km. 218 ° SW Antanambao, 1580 m. (B. L. Fisher).

Measurements of this material extend the range shown by the type-series: HL 0.45 - 0.48, HW 0.35 - 0.38, CI 77 - 82, ML 0.24, MI 49 - 53, SL 0.27 - 0.33, SI 78 - 86 (4 measured). Specimens from R. S. Manongarivo lack a pair of fine, short hairs that are curved towards the midline on the central pronotum.

S. glycon is distinguished from other species in the scotti-complex by having the mesonotum with only a single pair of erect hairs located at anterior margin, dorsum of petiole node reticulate-punctate, spongiform curtain of petiolar peduncle well developed, and cephalic dorsum with inconspicuous narrow filiform ground-pilosity.

S. glycon is part of closely related group of the eight smallest species in the scotticomplex with the dorsum of petiole node reticulate-punctate (all or at least some specimens of each species with HL> 0.54). The following matrix summarizes the key characters that help separate the members of this group. See discussion under lexex for characters that distinguish it from livens .

Character 1: number of pairs of hairs on mesonotum.

Character 2: number of pairs of hairs on pronotum, excluding the flagellate humeral hairs.

Character 3: Depth of spongiform curtain on ventral surface of petiolar peduncle.