Abelocephala longiceps, 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 : 175-178

Abelocephala longiceps sp. nov.

( Figs. 51 , 52, 63, 64 , 75 , 111–113 , 119 , 125 , 131, 137, 143)

Diagnosis. This species is easily recognized by the following combination of character states; however, to date only the male is known: body approximately 5.7 mm long; head approximately twice as long as width across eyes; rostral segment I more than twice as long as segment II; posterior pronotal lobe yellowish brown; outer (larger) cell of hemelytral membrane rounded apically; and posterior process of pygophore wide with rounded apical margin in dorsal view.

Description. Male (macropterous). Body ( Fig. 51 ) mostly brownish. Antennae and legs yellowish brown. Antennal flagella pale yellow. Rostrum and tibiae brownish yellow. Posterior pronotal lobe yellowish brown except for median longitudinal sulcus and posterior marginal area brown. Hemelytra dark brown except for extreme base and costal margin of corium brownish yellow. Abdomen yellowish brown.

Head ( Figs. 51 , 52, 63, 64 , 75 ) approximately twice as long as width across eyes, 1.1 times longer than pronotum; anteoculus 1.2 times longer than postoculus; mandibular plate ( Fig. 64 ) acutely angled at anterior corner and weakly projected anteriorly in dorsal view. Eye ( Figs. 63 , 75 ) approximately 0.35 times as wide as interocular space in dorsal view. Antennal segment I slender, approximately 10 times longer than its maximum width, as long as segment II ( Figs. 111, 112 ); flagellum as long as segment I ( Fig. 113 ). Rostral segment I slender, 2.2 times longer than segment II ( Fig. 75 ).

Pronotum ( Figs. 51 , 52) approximately 0.8 times as long as humeral width; anterior lobe 0.55 times as long as posterior lobe along midline, 0.6 times as wide as humeral width. Hemelytron ( Figs. 51 , 52, 119 ) 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 ( Figs. 52, 119 ) rounded apically.

Pygophore ( Fig. 125 ) ovoid in lateral view; posterior process (Fig. 131) wide, with rounded apical margin in dorsal view. Parameres ( Fig. 137 ) gently curved in apical three-fourths, with rounded, slightly projected apex in dorsal view. Struts of phallus ( Fig. 143 ) tapering apicad, weakly constricted in apical one-fourth, obtuse at apex, with lateral walls thinned throughout in dorsal view.

Female. Unknown.

Measurements [in mm, ♂ (n=3), holotype in parentheses]. Body length 5.47–5.87 (5.70). Head length 1.35–1.42 (1.42), width across eyes 0.75–0.82 (0.75). Lengths of antennal segments I and II 1.32–1.34 (1.34) and 1.23–1.30 (1.30), respectively. Lengths of rostral segments I and II 1.20–1.27 (1.20) and 0.53–0.60 (0.53), respectively. Pronotum length 1.13–1.33 (1.27), width across humeri 1.67–1.72 (1.67). Hemelytron length 4.83–5.53 (5.03). Lengths of femur and tibia of fore leg 1.58–1.66 (1.58) and 1.57–1.67 (1.65); of mid leg 1.53–1.63 (1.56) and 1.60–1.65 (1.65); of hind leg 2.03–2.18 (2.18) and 2.17–2.23 (2.17). Abdomen length 2.78–3.27 (2.82), maximum width 2.53–2.73 (2.62).

Holotype. ♂ ( Figs. 51 , 63, 64 , 75 , 111–113 , 119 , 125 , 131, 137, 143), “[ JAPAN] Mt. Yui-dake, Setouchi-chô, Amami-Ôshima Is., 21. IV. 2002, I. Kawashima” ( LETUA IC 2014-00223) ( TUA).

Paratypes (2 ♂). JAPAN [Amami-Oshima Is.] Mt. Yuwan-dake: 1 ♂ ( Fig. 52), 1.v.1986, Y. Notsu ( NSMT); 1 ♂, 18.vii.1963, Y. Kurosowa ( NSMT).

Distribution. Japan: Ryukyu Islands (Amami-Oshima Is.).

Etymology. From the Latin compound longiceps , referring to the long head; an adjective.

Remarks. In general appearance, the male of this new species resembles the male of A. major sp. nov. The male of A. longiceps sp. nov. is distinguished from the male of A. major sp. nov. by having the head approximately twice as long as the width across the eyes and not protuberant behind the eyes in dorsal view ( Fig. 63 ) [vs. approximately 1.5 times longer than the width across the eyes and roundly protuberant immediately behind the eyes in dorsal view ( Fig. 61 )], the mandibular plate acutely angled at the anterior corner in dorsal view ( Fig. 64 ) [vs. nearly right-angled at the anterior corner in dorsal view ( Fig. 62 )], and the length of antennal segment I approximately 10 times longer than the maximum width ( Fig. 111 ) [vs. approximately seven times longer than the maximum width ( Fig. 105 )].

Only three specimens of A. longiceps sp. nov. are known and no additional information regarding the biology of this reduviid is available. The three specimens were collected from moist forests of the Ryukyu Islands simultaneously with the other Japanese species of Abelocephala. This observation suggests that the habitat preference of A. longiceps sp. nov. is the same as those of the Japanese congeners.

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 59 – 64. Head (59, 61, 63) and anteoculus (60, 62, 64) of Abelocephala spp., male, dorsal view, antennae removed. 59, 60, A. yaeyamensis; 61, 62, A. major; 63, 64, A. longiceps. Abbreviation: mp, mandibular plate. Scale bars: 0.2 mm (59, 61, 63); 0.1 mm (60, 62, 64).

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 105 – 113. Left antenna of Abelocephala major (105 – 110) and A. longiceps (111 – 113), dorsal view, setae omitted. 105 – 107, 111 – 113, male; 108 – 110, female. 105, 108, 111, segment I; 106, 109, 112, segment II; 107, 110, 113, 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.