Leptogenys itoi

Workers selectively attack Isopoda, on which this species is thought to specialize (Itô, 2000; Leptogenys sp. 35 Itô, 1996).

Identification
Arimoto (2017) - In full-face view, head slightly longer than wide (CI: 93– 95). Mandible curved near base, becoming straight apically. Antennal scape long (SI: 99–110), surpassing posterior margin of head by two-fifths to one-third of its length. Clypeus with lateral lobe, with blunt angle between lateral lobe and median extension; median extension long, with broadly convex apex. In profile, petiole distinctly higher than long (LPI: 109–118), highest just anterior to posterodorsal angle; anterior face of node ventrally vertical and dorsally forming continuous curve with dorsum; dorsal face distinctly sloping anteriad.

Distribution
Malaysia: Peninsular Malaysia (Selangor and Pahang).

Distribution based on Regional Taxon Lists
Indo-Australian Region: Malaysia.

Nomenclature

 *  itoi. Leptogenys itoi Arimoto, 2017: 91, figs. 3, 8, 9, 10, 15A, 16B, 17A, 18B (w.q.m.) MALAYSIA.

Worker
(n = 5, holotype in parentheses). HL: 1.66–1.73 (1.73), HLL: 1.12–1.18 (1.18), HLA: 0.13–0.15 (0.14), HW: 1.54–1.64 (1.64), CML: 0.29–0.36 (0.35), CI: 93–95 (95), CLI: 17–21 (20), SL: 1.57–1.80 (1.80), SI: 99–110 (110), EL: 0.31–0.35 (0.35), OI: 28–30 (30), PrL: 0.99–1.10 (1.10), PrH: 0.67–0.80 (0.79), PrW: 1.00–1.07 (1.05), WL: 2.47–2.72 (2.72), PeL: 0.84–0.95 (0.95), PeH: 0.99– 1.04 (1.04), PeW: 0.68–0.74 (0.74), LPI: 109–118 (109), DPI: 76–84 (78).

In full face view, head slightly longer than wide. Mandible curved near base, becoming straight apically; subapical tooth obsolete. Eye prominent, measuring one-fourth to one-third of head lateral margin length. Antennal scape longer than width of head, surpassing posterior margin of head by two-fifths to one-third of its length; antennomere III ca. 2.5 times as long as wide. Clypeus with lateral lobe, with blunt angle between lateral lobe and median extension; median extension long, with broadly convex apex. In dorsal view, pronotum almost as long as wide. Metanotal groove slightly impressed. In profile, propodeal dorsum almost straight. Petiole in profile distinctly higher than long, highest just anterior to posterodorsal angle of node, with fan-shaped node; anterior face of node ventrally vertical and dorsally forming continuous curve with dorsum; dorsal face distinctly sloping anteriad; posterior face slightly concave dorsally and slightly convex ventrally.

Head strongly areolate-rugose, longitudinally striate near clypeus; vertex weakly and transversally striate. Mandible weakly striate longitudinally. Prosternum smooth and without punctures. Gastral segment I with scalloped depressions that are irregular in size; distance between depressions distinctly greater than diameter of depressions; interspace between depressions with small punctures; segments II smooth.

Body black, slightly tinged with red; clypeus, mandible, antenna, legs and ventral half of petiole dark-red. Apical two or three segments of gaster red-brown. Scalloped depressions on gastral segment I bearing hairs; small punctures without hairs.

Queen
(n = 5). HL: 1.58–1.68, HLL: 1.07–1.14, HLA: 0.10– 0.14, HW: 1.43–1.59, CML: 0.29–0.34, CI: 89–94, CLI: 18–20, SL: 1.51–1.62, SI: 102–107, EL: 0.30–0.36, OI: 27–31, PrL: 0.98–1.09, PrH: 0.66–0.79, PrW: 1.01–1.09, WL: 2.40–2.72, PeL: 0.84–0.90, PeH: 1.02–1.07, PeW: 0.72–0.78, LPI: 119–126, DPI: 85–90. Mandible shorter than that of worker. Petiole in profile distinctly higher than long, in dorsal view distinctly longer than wide.

Male
(n = 2). HL: 1.08–1.17, HW: 0.83–0.87, CML: 0.35–0.38, CI: 75–77, CLI: 33, EL: 0.63–0.64, MeL: 1.01-1.10, MeW: 1.05–1.20, WL: 2.44– 2.59, PeL: 0.68–0.75, PeH: 0.81–0.85, PeW: 0.54, LPI: 113–120, DPI: 71–80.

In full-face view, head longer than wide excluding eyes, wider posteriorly; posterior margin distinctly rounded. Mandible small, without basal angle and denticles, with rounded apex. Eye occupying over half of head length. Three prominent ocelli present; maximum length of lateral ocellus shorter than minimum distance between lateral ocellus and eye. Antenna 13-segmented; scape distinctly shorter than width of head; antennomere II shortest, roughly as long as wide; III longest; XIII shorter than III. Clypeus triangular and projecting anteriad, convex on midline; anterolateral margin straight; apex moderately acute; epistomal suture broadly rounded. Mesoscutum in profile convex, in dorsal view shorter than wide, widest posterior to mid-length; notaulus weakly notable; parapsidal line more than half of mesoscutal length; transscutal line almost straight. Anterior margin of mesoscutellar disc rounded. In profile, propodeal dorsum forming continuous curve with declivity; metapleural-propodeal sulcus present. Forewing ca. 3.0 times as long as wide, with stigma. Hindwing less than 0.8 times as long as forewing. Petiole in profile higher than long, in dorsal view longer than wide, highest posteriorly, with short peduncle, with fan-shaped node; anterior and dorsal faces forming convex line; dorsal face sloping anteriad; posterior face convex; in dorsal view, lateral margin broadly convex. With waist in profile, anterior lobe of subpetiolar process short-subtriangular, anterior margin convex, ventral apex moderately acute, posterior margin concave. With gaster in profile, prora low, long; continuously curved between prora and anteroventral edge of gastral sternite I. Constriction between gastral segments I and II distinct.

Head, mesosoma, and petiole weakly rugose, with piligerous small punctures. Mandible smooth. Clypeus with oblique to longitudinal striae. Subpetiolar process finely striate. Gastral segment I with irregularly sized depressions; distance between depressions distinctly greater than diameter of depressions; interspace between depressions with small punctures; segments II–V smooth; constriction between gastral segments I and II finely scrobiculate.

Body black, tinged with red; clypeus, mandible, antenna, legs, subpetiolar process, and gaster red-brown. Hairs of various lengths, scattered, white-yellow; antennal scape and legs with dense short pubescence, mixed with long scattered hairs. Scalloped depressions and small punctures on gastral segment I bearing hairs.

Type Material
Holotype. Worker (FI99-240), transporting woodlouse, secondary rainforest, Ulu Gombak, Gombak, Selangor, Malaysia, 3.32°N, 101.75°E, 230–350 m, 3 VI 1999, Fuminori Itô leg. . Paratypes (47 workers, 6 queens, 2 male). 1 worker (FI92MG-270-5), same place as the holotype, VII-X 1992, Fuminori Itô leg. [BLKU]; 1 worker (FI92MG-270-7), same place, VII-X 1992, Fuminori Itô leg. [BLKU]; 2 workers, 1 queen (FI92MG-366), same place, VII-X 1992, Fuminori Itô leg. [1 worker, 1 queen: BLKU; 1 worker: ]; 6 workers (FI92MG-456), 2 workers (FI92MG-463), same place, VII-X 1992, Fuminori Itô leg. [BLKU]; 4 workers (FI92MG-518), same place, VII-X 1992, Fuminori Itô leg. [3 worker: BLKU; 1 worker: SKYC]; 4 workers, 1 male (BG99-2), same place, V 1999, Bruno Gobin leg. [BLKU]; 4 workers (FI04-119), same place, 19 XII 2004, Fuminori Itô leg. [BLKU]; 6 workers, 1 queen, 1 male (FI04-120), same place, 17 XII 2004, Fuminori Itô leg. [BLKU]; 8 workers, 1 queen (AG05-20), same place, VII 2005, Ayako Gotô leg. [BLKU]; 1 worker, same place, 3 XII 2005, Seiki Yamane leg. [SKYC]; 3 workers, 1 queen (FI11-16), same place, 13 III 2011, Fuminori Itô leg. [BLKU]; 3 workers, 2 queens (FI11-17), same place, 13 III 2011, Fuminori Itô leg. [BLKU]; 1 worker, forest near road, Gap, Selangor, Malaysia, 900m, 14 III 1993, Löbl and Calame ; 1worker, Fraser’s Hill, below Kuantun Ridge, Pahang, Malaysia, 1,350m, 17 III 1993, Löbl and Calame leg. (MSNG).

Etymology
Dedicated to Professor Fuminori Itô, collector of the material examined.