Giraffaenictus eguchii Maruyama, 2008

Chinese common name: Ĵ口KDZdzûDz

(Figs 1–5)

Maruyama, 2008: 53 (description; illustrations; type locality: [Vietnam]: W. Yen Tu (637 feet, 21°10′52.2″ 106°43′41.3″), Bac Giang Province).

Material examined. CHINA, Yunnan: • 2♂♂ 1♀ (MYNU), Dehong Prefecture, Mangshi, Hexinchang Village [ñù场"], Yingpanpo [äâ坡], in nest of Aenictus binghami, 17.XI.2024, Yao Zhang [张尧] leg.; • 1ex (cYJL), same data as previous; • 1♂ 2♀♀ (cXBS), 1ex (cHYX), same data as previous except 31.X.2024; • 1♂ 1ex (cXBS), Xishuangbanna, Mengla County, Menglun Town, near Xishuangbanna Tropical Botanical Garden [Ʊ双Dzaeüū 园], in nest of Aenictus sp., alt. 700 m, 8.VIII.2018, Xiao-Bin Song [Ṫăė] leg.

Description. Female (Figs 1A–C; 2C, E; 3A–E). Measurements. Body 3.7 mm long, widest near posterior margin of abdominal segment V, 4.7 times as long as wide. Lengths of body parts: forebody 2.0 mm, head 0.7 mm, eye 0.2 mm, antenna 1.7 mm, pronotum 0.6 mm, elytra 0.7 mm, metatibia 1.4 mm, abdomen 1.7 mm; widths: head 0.4 mm, pronotum 0.5 mm, elytra 0.7 mm, abdomen 0.8 mm.

Habitus (Figs 1A–C; 2C). Body myrmecoid, elongately slender, with long and slender appendages. Dorsum of head except posterior part, posterior part of scutellar shield, elytra, most of meso- and metaventrites, tibiae, tarsi, and abdomen after anterior part of segment IV shinning; other parts matt. Body almost entirely reddish brown; appendages with distal parts paler in various degree. Body predominantly covered with moderately long, erect, yellowish-brown setae.

Head elongate, slightly convex dorsally, widest at eyes, 1.6 times as long as wide. Dorsum closely granulate in posterior part; other parts smooth, rather sparsely covered with fine punctures, interstices lacking microsculpture. Clypeus transverse, straight at anterior margin; surface most impunctate, with paired paramedian setae. Frontoclypeal suture absent. Frons concave. Antennal tubercles prominent. Eyes prominent, situated around apical 1/6 of head, 0.24 times as long as head, ommatidia identifiable. Posterior angles dentiform, posterolaterally projecting. Neck region 3/8 width of head capsule. Gular sutures subparallel-sided.

Mouthparts. Labrum transverse, deeply and roundly emarginate in middle of anterior margin. Mandibles sickleshaped, long, constantly curved and gradually tapered towards acute apices, with inner margin slightly sinuate. Maxillary palpi with four palpomeres, long and slender, with terminal palpomere rather thin and slender. Labial palpi with three palpomeres, small and slender, with terminal palpomere slightly dilated. Mentum subtrapezoidal, deeply and roundly emarginate in middle of anterior margin.

Antennae (Fig. 2E) long, thick, about 0.8 times as long as forebody, 3.9 times as long as head width.Antennomeres with length ratio from scape to antennomere 11 as follows: 3.4: 1.8: 1.3: 1.0: 1.4: 1.4: 1.5: 1.4: 1.2: 1.2: 3.0. All antennomeres longer than wide; scape clavate, longest, longer than pedicel and antennomere 3 combined, thicker than other antennomeres; antennomere 4 shortest; antennomere 11 spindle-shaped, second longest, 2.2 times as long as wide.

Pronotum subpyriform, constricted in about posterior half, slightly convex dorsally, widest at anterior 1/4, 1.2 times as long as wide, 1.3 times as wide as head. Anterior margin emarginate in middle; posterior margin simply rounded. Posterior angles round. Surface closely granulate throughout, with an inconspicuous fine sulcus along mid-line.

Scutellar shield linguiform, rounded at apex. Surface closely granulate in about anterior half while impunctate in about posterior half.

Elytra, together with meso- and metaventrites, globular, widest at middle, as wide as long, 1.3 times as wide as and 1.1 times as long as pronotum, with apical parts apart. Lateral margins evenly arcuate; apicolateral angles obtuse. Dorsum smooth, rather sparsely covered with fine punctures; interstices lacking microsculpture. Wings fully developed.

Legs long and slender. Coxae elongate; metacoxae arciform. Femora fusiform; metafemora slightly longer than metatibiae. Tibiae thin, straight, without apical spurs. Tarsi simple, filiform; metatarsomeres 1–5 with length ratio as follows: 8.5: 2.7: 1.9: 1.0: 2.3. Claws rather thin, simply curved.

Abdomen club-shaped, 2.1 times as long as wide, 4/5 length of forebody, 1.1 times as wide as elytra, widest at about posterior 1/7 of segment V. Surface closely granulate from segment II to anterior part of segment IV; other parts smooth, rather sparsely covered with fine punctures, interstices lacking microsculpture. Tergite II semicircular; segment III rather narrowly cylindrical except slightly dilated anterior end; segment IV trumpet-shaped, strongly constricted anteriorly; posterior half of segment IV to segment VIII constitute globular ‘pseudogaster’.

Female terminalia and genitalia. Tergite VIII (Fig. 3A) semicircular, rounded at posterior margin; sternite VIII (Fig. 3B) transversely subelliptical, slightly protruded in middle of posterior margin. Tergite IX (Fig. 3D) unmodified. Tergite X (Fig. 3C) linguiform, rounded at posterior margin. Spermatheca (Fig. 3C–E) ‘S’-shaped.

Male (Figs 2A, C, F; 4A–C; 5A–F). Measurements. Body 3.4–3.8 mm long, widest near posterior margin of abdominal segment V, 4.6–4.8 times as long as wide. Lengths of body parts: forebody 1.9–2.0 mm, head 0.6–0.7 mm, eye 0.1–0.2 mm, antenna 1.7–1.9 mm, pronotum 0.6– 0.6 mm, elytra 0.7– 0.7 mm, metatibia 1.3–1.5 mm, abdomen 1.5–1.7 mm; widths: head 0.4– 0.4 mm, pronotum 0.5– 0.5 mm, elytra 0.7– 0.7 mm, abdomen 0.7–0.8 mm.

For a detailed description of the external morphology of male, refer to Maruyama (2008).

Male Terminalia and genitalia. Tergite VIII (Fig. 4A) subtrapezoidal, almost truncated at posterior margin; sternite VIII (Fig. 4B) transversely subelliptical, moderately protruded in middle of posterior margin. Tergite IX (Fig. 4C) unmodified. Tergite X (Fig. 4C) linguiform, rounded at posterior margin. Aedeagal median lobe (Fig. 5A– C) narrowed apically in ventral view; basal capsule projected ventrally; distal costa short in lateral view; copulatory piece acuminated apically. Paramere (Fig. 5D–F) with paramerite approximately twice as wide as condylite; apical lobe digitiform, short, with 4 minute setae in apical part.

The sexual dimorphism in external morphology exhibited by G. eguchii is minimal; nevertheless, several differences are discernible in the following characters (those of female in parentheses): in male, antennae relatively longer, 4.1–4.4 times as long as head width (3.9 times); tergite VIII subtrapezoidal, almost truncated at posterior margin (semicircular, rounded at posterior margin); sternite VIII moderately protruded in middle of posterior margin (slightly protruded in middle of posterior margin).

Host. Aenictus binghami Forel, 1900 (Fig. 2D).

Distribution. China (Yunnan), Vietnam (Fig. 6).

Remarks. In the original description, G. eguchii was provisionally placed in the tribe Aenictoteratini by Maruyama (2008), reflecting morphological affinities with myrmecophilous genera Aenictoteras Wheeler, 1932 and Rosciszewskia Kistner, 1993. In a following molecular phylogenetic study, Giraffaenictus emerged as sister to the Mimanommatini genus Dorylophila Wasmann, 1904, within the “ Pygostenini ” clade (Maruyama & Parker 2017). Recently, in the phylogenetic review of Orlov et al. (2021), Giraffaenictus was found within Mimanommatini, thereby rendering the latter tribe paraphyletic. The precise taxonomic placement of this species remains unresolved and warrants further verification through additional study.