Abelocephala albula, Ishikawa, Tadashi, Cai, Wanzhi & Tomokuni, Masaaki, 2015

Ishikawa, Tadashi, Cai, Wanzhi & Tomokuni, Masaaki, 2015, The assassin bug subfamily Tribelocephalinae (Hemiptera: Heteroptera: Reduviidae) from Japan, with descriptions of eight new species in the genera Opistoplatys and Abelocephala, Zootaxa 3936 (2), pp. 151-180 : 161-164

Abelocephala albula sp. nov.

( Figs. 41, 42 , 53, 54 , 65 , 70 , 76 , 81–86 , 114 , 120 , 126, 132, 138, 144, 149)

Diagnosis. This species is recognized by the following combination of character states: body approximately 3 mm long; head 1.4 to 1.5 times longer than width across eyes; mandibular plate nearly right-angled at anterior corner and weakly projected anteriorly in dorsal view; posterior pronotal lobe whitish to pale yellow; outer (larger) cell of hemelytral membrane acutely angled apically; and posterior process of pygophore wide with straight apical margin in dorsal view.

Description. Male (macropterous). Body ( Fig. 41 ) mostly brownish. Antennae, rostrum, and legs brownish yellow. Antennal flagella pale yellow. Posterior pronotal lobe whitish to pale yellow except for median longitudinal sulcus and posterior marginal area brownish. Hemelytra brown, with basal part pale yellow to pale brown; corial cell more or less fuscous ( Fig. 41 ). Abdomen yellowish brown to brown.

Head ( Figs. 41 , 53, 54 , 70 ) approximately 1.4 times longer than width across eyes, as long as pronotum; anteoculus 1.1 times longer than postoculus; mandibular plate ( Fig. 54 ) nearly right-angled at anterior corner and weakly projected anteriorly in dorsal view. Eye ( Figs. 53 , 70 ) approximately 0.35 times as wide as interocular space in dorsal view. Antennal segment I slender, approximately 8.5 times longer than its maximum width, as long as segment II ( Figs. 81, 82 ); flagellum as long as segment I ( Fig. 83 ). Rostral segment I stout, 1.5 times longer than segment II ( Fig. 70 ).

Pronotum ( Fig. 41 ) approximately 0.7 times as long as humeral width; anterior lobe 0.6 times as long as posterior lobe along midline, 0.7 times as wide as humeral width. Hemelytron ( Figs. 41 , 114 ) wide, twice as long as its maximum width, exceeding apex of abdomen by approximately 0.35 times of its length; outer (larger) cell of membrane ( Fig. 114 ) acutely angled apically.

Pygophore ( Fig. 120 ) somewhat compressed dorsoventrally; posterior process (Fig. 126) wide, with straight apical margin in dorsal view. Parameres ( Fig. 132 ) weakly curved in apical two-thirds, with obtuse, inwardly projected apex in dorsal view. Struts of phallus ( Fig. 138 ) tapering apicad, obtuse at apex, and with lateral walls thickened at its base in dorsal view.

Female (micropterous). At first sight, obviously differing from male due to micropterous condition ( Fig. 42 ). Head ( Figs. 42 , 65 , 76 ) approximately 1.5 times longer than width across eyes, approximately 1.2 times longer than pronotum; anteoculus 0.9 times as long as postoculus. Eye ( Figs. 65 , 76 ) small, approximately 0.2 times as wide as interocular space in dorsal view. Antennal segment I stouter and much shorter than that of male, approximately 5.5 times longer than its maximum width, a little longer than segment II ( Figs. 84, 85 ); flagellum approximately 1.2 times longer than segment I ( Fig. 86 ). Rostral segment I stout, 1.4 times longer than segment II ( Fig. 76 ). Pronotum ( Fig. 42 ) approximately 0.85 times as long as humeral width; anterior lobe 1.1 times longer than posterior lobe along midline, as wide as humeral width. Hemelytra ( Fig. 42 ) small, pad-like, reaching to posterior margin of abdominal tergite II; venation inconspicuous. Abdominal tergite IX ( Fig. 144 ) with lateral projection at each basal angle; lateral projection short, tapering in apical part, obtuse at apex. Valvifer I ( Fig. 149 ) oblong; valvula I ( Fig. 149 ) with approximately 4 setae.

Measurements [in mm, ♂ (n=51) /♀ (n=8), holotype in parentheses]. Body length 2.76–3.17/2.91–3.17 (3.00). Head length 0.66–0.74/0.71–0.74 (0.72), width across eyes 0.53–0.57/0.47–0.49 (0.54). Lengths of antennal segments I and II 0.72–0.80/0.55–0.56 (0.77) and 0.71–0.77/0.49–0.53 (0.74), respectively. Lengths of rostral segments I and II 0.49–0.55/0.52–0.56 (0.49) and 0.31–0.35/0.30–0.35 (0.34), respectively. Pronotum length 0.66–0.67/0.53–0.60 (0.67), width across humeri 0.92–1.01/0.63–0.68 (0.99). Hemelytron length 2.74–2.82/ 0.37–0.46 (2.74). Lengths of femur and tibia of fore leg 0.86–0.98/0.78–0.87 (0.95) and 0.91–1.00/0.80–0.85 (0.98); of mid leg 0.84–0.91/0.71–0.83 (0.88) and 0.87–0.95/0.79–0.81 (0.88); of hind leg 1.08–1.21/0.98–1.05 (1.19) and 1.15–1.31/1.01–1.09 (1.26). Abdomen length 1.44–1.67/1.57–1.66 (1.56), maximum width 1.22–1.44/ 1.40–1.59 (1.34).

Holotype. ♂ ( Fig. 41 ), “[ JAPAN] Komi, Iriomote-jima Is., the Ryûkyûs, 23–27.IV.2004, FIT, T. Ishikawa et al.” ( LETUA IC 2014-00069) ( TUA).

Paratypes (50 ♂, 8 ♀). JAPAN [Ishigaki Is.] Shiramizu: 1 ♂, 1 ♀ ( Fig. 42 ), 15.vi.2003, H. Mizushima ( LETUA IC 2014-00070–00071) ( TUA), 1 ♂, 3–6.v.2004, FIT-M, T. Ishikawa ( LETUA IC 2014-00072) ( TUA). Mt. Omoto-dake: 2 ♀, 16.vi.2003, H. Mizushima ( LETUA IC 2014-00073–00074) ( TUA). [Iriomote Is.] Haemidahama: 1 ♀, 30.v.1999, K. Takahashi ( LETUA IC 2014-00075) ( TUA). Ôtomi-rindô: 2 ♂ (one shown in Fig. 114 ), 7–11.vi.2002, Malaise trap, T. Tsuru ( LETUA IC 2014-00076–00077) ( TUA), 1 ♀, 23.iv.2004, T. Ishikawa ( LETUA IC 2014-00078) ( TUA), 1 ♂, 26.iv.2004, T. Ishikawa ( LETUA IC 2014-00079) ( TUA). Fusatoruba, Ôhara: 1 ♀ ( Figs. 144 , 149 ), 29.v.2000, H. Mizushima ( LETUA IC 2014-00080) ( TUA). Komi: 1 ♂, 2.iii.2002, T. Ishikawa ( LETUA IC 2014-00081) ( TUA), 2 ♀ (one shown in Figs. 65 , 76 , 84–86 ), 2.v.2002, S. Nagashima ( LETUA IC 2014-00082–00083) ( TUA), 1 ♂, 1.iv.2003, S. Nagashima ( LETUA IC 2014-00084) ( TUA), 28 ♂ (each one shown in Figs. 53, 54 , 70 , 81–83 , 132 , and Figs. 120 , 126, 138), same data as holotype ( LETUA IC 2014-00085–00112) ( TUA, CAU, NSMT). Near Aira-gawa: 1 ♂, 28.iv.2003, T. Kurihara ( LETUA IC 2014-00113) ( TUA). Funaura: 3 ♂, 6–11.iv.2005, FIT-M, J. Kantoh ( LETUA IC 2014-00114–00116) ( TUA). Shirahama: 11 ♂, 23–27.iv.2004, FIT-M, T. Ishikawa et al. ( LETUA IC 2014-00117–00127) ( TUA).

Distribution. Japan: Ryukyu Islands (Ishigaki Is., Iriomote Is.).

Etymology. From the Latin albula , referring to the whitish to pale yellow pronotum; an adjective.

Remarks. Macropterous males and micropterous females of this species are known. In general habitus, this new species resembles Abelocephala thai , which is the type species of the genus, known from Thailand ( Maldonado Capriles 1996). The male of A. albula sp. nov. can be distinguished from the male of A. thai by the longer head [approximately 1.4 times longer than the width across the eyes ( Fig. 53 ) vs. approximately 1.1 times longer than width across the eyes], shorter antennal flagellum [as long as antennal segment I ( Figs. 81, 83 ) vs. approximately 1.2 times longer than antennal segment I], shorter rostral segment I [1.4 times longer than segment II ( Fig. 70 ) vs. approximately 3 times longer than segment II], and acutely angled outer (larger) cell of the hemelytral membrane at apex ( Fig. 114 ) (vs. rounded angled outer (larger) cell of the hemelytral membrane at apex). We were unable to compare females between these two species because no female specimens of A. thai were available.

Many male specimens (all with macropterous wings) examined in the present study were collected from FIT- Ms or a Malaise trap placed in humid forests. This finding suggests that the males fly actively near the forest floor. All the females (with micropterous wings) and a few males were collected directly from forest leaf litter.

Figures

FIGURES 41 – 51. Abelocephala spp., habitus in dorsal view. 41, 42, A. albula; 43, 44, A. araiorum; 45, 46, A. nakatai; 47, 48, A. yaeyamensis; 49, 50, A. major; 51, A. longiceps. 41, 43, 45, 47, 49, 51, male; 42, 44, 46, 48, 50, female. Scale bars: 1 mm.

FIGURES 53 – 58. Head (53, 55, 57) and anteoculus (54, 56, 58) of Abelocephala spp., male, dorsal view, antennae removed. 53, 54, A. albula; 55, 56, A. araiorum; 57, 58, A. nakatai. Abbreviation: mp, mandibular plate. Scale bars: 0.2 mm (53, 55, 57); 0.1 mm (54, 56, 58).

FIGURES 65 – 69. Head of Abelocephala spp., female, dorsal view, antennae removed. 65, A. albula; 66, A. araiorum; 67, A. nakatai; 68, A. yaeyamensis; 69, A. major. Scale bars: 0.2 mm.

FIGURES 70 – 75. Head of Abelocephala spp., male, lateral view, antennae removed. 70, A. albula; 71, A. araiorum; 72, A. nakatai; 73, A. yaeyamensis; 74, A. major; 75, A. longiceps. Scale bars: 0.2 mm (70 – 72); 0.5 mm (73 – 75).

FIGURES 76 – 80. Head of Abelocephala spp., female, lateral view, antennae removed. 76, A. albula; 77, A. araiorum; 78, A. nakatai; 79, A. yaeyamensis; 80, A. major. Scale bars: 0.2 mm (76 – 78); 0.5 mm (79, 80).

FIGURES 81 – 92. Left antenna of Abelocephala albula (81 – 86) and A. araiorum (87 – 92), dorsal view, setae omitted. 81 – 83, 87 – 89, male; 84 – 86, 90 – 92, female. 81, 84, 87, 90, segment I; 82, 85, 88, 91, segment II; 83, 86, 89, 92 flagellum. Scale bar: 0.2 mm.

FIGURES 114 – 119. Right hemelytron of male Abelocephala spp. 114, A. albula; 115, A. araiorum; 116, A. nakatai; 117, A. yaeyamensis; 118, A. major; 119, A. longiceps. Scale bars: 1 mm.

FIGURES 120 – 125. Pygophore of Abelocephala spp., lateral view, setae omitted. 120, A. albula; 121, A. araiorum; 122, A. nakatai; 123, A. yaeyamensis; 124, A. major; 125, A. longiceps. Scale bars: 0.2 mm.

FIGURES 132 – 137. Paramere of Abelocephala spp., dorsal view. 132, A. albula; 133, A. araiorum; 134, A. nakatai; 135, A. yaeyamensis; 136, A. major; 137, A. longiceps. Scale bars: 0.1 mm.

FIGURES 138 – 143. Struts of Abelocephala spp., dorsal view. 138, A. albula; 139, A. araiorum; 140, A. nakatai; 141, A. yaeyamensis; 142, A. major; 143, A. longiceps. Scale bars: 0.1 mm.

FIGURES 144 – 148. Female abdominal tergite IX of Abelocephala spp., dorsal view, setae omitted. 144, A. albula; 145, A. araiorum; 146, A. nakatai; 147, A. yaeyamensis; 148, A. major. Abbreviation: lp, lateral projection. Scale bars: 0.1 mm.

FIGURES 149 – 153. Valvifer I and valvula I of Abelocephala spp., setae on valvifer I omitted. 149, A. albula; 150, A. araiorum; 151, A. nakatai; 152, A. yaeyamensis; 153, A. major. Abbreviations: vf, valvifer I; vl, valvula I. Scale bars: 0.2 mm.