Abelocephala araiorum sp. nov.

(Figs. 43, 44, 55, 56, 66, 71, 77, 87–92, 115, 121, 127, 133, 139, 145, 150)

Diagnosis. This species is recognized by the following combination of character states: body approximately 3 mm long; head 1.6 to 1.7 times longer than width across eyes; mandibular plate nearly right-angled at anterior corner and weakly projected anteriorly in dorsal view; posterior pronotal lobe brownish yellow; outer (larger) cell of hemelytral membrane acutely angled apically; and posterior process of pygophore wide with weakly curved apical margin in dorsal view.

Description. Male (macropterous). Body (Fig. 43) mostly brownish. Antennae, rostrum, and legs brownish yellow. Antennal flagella pale yellow. Posterior pronotal lobe brownish yellow except for median longitudinal sulcus and posterior marginal area brownish. Hemelytra brown, with basal part pale yellow to pale brown; corial cell evenly pale (Fig. 43). Abdomen yellowish brown to brown.

Head (Figs. 43, 55, 56, 71) approximately 1.6 times longer than width across eyes, 1.1 times longer than pronotum; anteoculus longer than postoculus; mandibular plate (Fig. 56) nearly right-angled at anterior corner and weakly projected anteriorly in dorsal view. Eye (Figs. 52, 71) approximately 0.3 times as wide as interocular space in dorsal view. Antennal segment I slender, approximately 8 times longer than its maximum width, as long as segment II (Figs. 87, 88); flagellum as long as segment I (Fig. 89). Rostral segment I stout, 1.5 times longer than segment II (Fig. 71).

Pronotum (Fig. 43) approximately 0.8 times as long as humeral width; anterior lobe 0.7 times as long as posterior lobe along midline, 0.7 times as wide as humeral width. Hemelytron (Figs. 43, 115) wide, twice as long as its maximum width, exceeding apex of abdomen by approximately 0.3 times of its length; outer (larger) cell of membrane (Fig. 115) acutely angled apically.

Pygophore (Fig. 121) elliptical in lateral view; posterior process (Fig. 127) wide, with weakly curved apical margin in dorsal view. Parameres (Fig. 133) weakly curved in apical two-thirds, with obtuse, inwardly projected apex in dorsal view. Struts of phallus (Fig. 139) tapering apicad, gently widened at around apical two-fifths, obtuse at apex, and with lateral walls thinned at its base in dorsal view.

Female (micropterous). At a glance, quite different from male because of micropterous condition (Fig. 44). Head (Figs. 44, 66, 77) approximately 1.7 times longer than width across eyes, 1.4 times longer than pronotum. Eye (Figs. 66, 77) small, approximately 0.2 times as wide as interocular space in dorsal view. Antennal segment I stouter and shorter than that of male, approximately 5.5 times longer than its maximum width, a little longer than segment II (Figs. 90, 91); flagellum approximately 1.2 times longer than segment I (Fig. 92). Anterior pronotal lobe 1.5 times longer than posterior lobe along midline, 1.1 times wider than humeral width (Fig. 44). Hemelytra (Fig. 44) small, pad-like, reaching to posterior margin of abdominal tergite II; venation inconspicuous. Abdominal tergite IX (Fig. 145) with lateral projection at each basal angle; lateral projection short and wide, rounded at apex. Valvifer I (Fig. 150) oblong; valvula I (Fig. 150) with approximately 2 setae.

Measurements [in mm, ♂ (n=5) /♀ (n=2), holotype in parentheses]. Body length 3.00–3.19/3.36–3.55 (3.00). Head length 0.68–0.77/0.77–0.81 (0.70), width across eyes 0.48–0.50/0.49–0.51 (0.50). Lengths of antennal segments I and II 0.69–0.79/0.60–0.63 (0.72) and 0.66–0.77/0.53–0.57 (0.67), respectively. Lengths of rostral segments I and II 0.49–0.55/0.55–0.56 (0.49) and 0.33–0.35/0.37–0.39 (0.33), respectively. Pronotum length 0.60–0.68/0.49–0.60 (0.67), width across humeri 0.82–0.96/0.66–0.70 (0.88). Hemelytron length 2.53–2.75/ 0.50–0.52 (2.74). Lengths of femur and tibia of fore leg 0.84–0.98/0.83–0.88 (0.85) and 0.87–0.98/0.84–0.88 (0.90); of mid leg 0.79–0.93/0.79–0.84 (0.84) and 0.84–0.93/0.78–0.85 (0.84); of hind leg 1.10–1.27/1.03–1.12 (1.12) and 1.16–1.30/1.09–1.14 (1.19). Abdomen length 1.45–1.73/1.88–2.00 (1.56), maximum width 1.23–1.32/ 1.46–1.70 (1.32).

Holotype. ♂ (Fig. 43), “[JAPAN] Kubura-dake, Yonaguni-jima Is., Ryûkyû Islands, 9–12. IX. 2004, FIT, Koji & Shiho Arai” (LETUA IC 2014-00128) (TUA).

Paratypes (4 ♂, 2 ♀). JAPAN [Yonaguni Is.] Mt. Kubura-dake: 2 ♂ (one shown in Figs. 121, 127, 133, 139), 1 ♀ (Figs. 44, 66, 77, 90–92, 145, 150), 16.vi.2001, S. Arai (LETUA IC 2014-00129–00131) (TUA, CAU), 1 ♂ (Figs. 55, 56, 71, 87–89, 115), 28.iv.–2.v.2004, FIT-M, T. Ishikawa et al. (LETUA IC 2014-00132) (TUA), 1 ♀, 10.ix.2004, K. & S. Arai (LETUA IC 2014-00133) (TUA), 1 ♂, same data as holotype (LETUA IC 2014-00134) (NSMT).

Distribution. Japan: Ryukyu Islands (Yonaguni Is.).

Etymology. Named after Mr. Koji Arai and his wife Shiho, who collected the type specimens of this species; a noun in the genitive case.

Remarks. Only macropterous males and micropterous females are known in this species. In general appearance, this new species is very similar to A. albula sp. nov. The male of A. araiorum sp. nov. is distinguished from the male of A. albula sp. nov. by its larger head [approximately 1.6 times longer than the width across the eyes (Fig. 55) vs. approximately 1.4 times longer than the width across the eyes (Fig. 53)], the corial cell evenly pale (Fig. 43) [vs. more or less fuscous (Fig. 41)], the posterior process of the pygophore with a weakly curved apical margin in dorsal view (Fig. 127) [vs. with a straight apical margin in dorsal view (Fig. 126)], and the struts of the phallus gently widened at approximately two-fifths in dorsal view (Fig. 139) [vs. not widened in dorsal view (Fig. 138)]. The female of A. araiorum sp. nov. is distinguished from the female of A. albula sp. nov. by its larger head [approximately 1.7 times longer than the width across the eyes (Fig. 66) and approximately 1.4 times longer than the pronotum (Fig. 44) [vs. approximately 1.5 times longer than the width across eyes and approximately 1.2 times longer than the pronotum (Figs. 42, 65)], the length of the anterior pronotal lobe [1.5 times longer than the posterior lobe along the midline (Fig. 44) vs. 1.1 times longer than the posterior lobe along the midline (Fig. 42)], the lateral projections of abdominal tergite IX wide in the apical parts and rounded at the apices (Fig. 145) [vs. tapering in the apical parts and obtuse at the apices (Fig. 144)], and valvula I with approximately two setae (Fig. 150) [vs. with approximately four setae (Fig. 149)].

Abelocephala araiorum sp. nov. was collected from FIT-Ms placed on the forest floor and by using a Tullgren funnel. These observations suggest that, similar to A. albula sp. nov., this new species is a ground inhabitant.