Sadoletus izzardi Hidaka

Ban, Teruaki & Ishikawa, Tadashi, 2013, The lygaeoid bug genus Sadoletus Distant (Hemiptera: Heteroptera: Heterogastridae) from Japan, Zootaxa 3609 (2), pp. 195-203 : 196-201

Sadoletus izzardi Hidaka

( Figs. 1 , 5 , 8–14 )

Sadoletus izzardi Hidaka, 1959: 199 ; Slater, 1964: 776; Miyoshi, 1997: 43.

Material examined. Non-types: 22 3 14 Ƥ (NSMT, TUA) — Honshu [Yamaguchi Pref.] 1 3, Oomine Pass, Hikari-shi, 12.II.1997, K. Miyoshi; 1 Ƥ, Hikari-shi, 19.II.1997, K. Miyoshi; 5 3 1 Ƥ, Haginodaira, Hikari-shi, 18.VII.2009, TB; 15 3 10 Ƥ, Mt. Senbou, Hikari-shi, 18.VII.2009, TB. Shikoku [Ehime Pref.] 1 3, Sugitate, 16.V.1951, M. Miyatake; 1 Ƥ, Sugitate, Matsuyama, 31.III.1953, T. Mohri; 1 Ƥ, Matsuyama, Fumoto, 9.VII.1998, S. Yano.

Diagnosis. Recognized among congeners of Sadoletus by a combination of the following characters: head about two-thirds as long as width across eyes ( Fig. 1 ); antennae almost brownish yellow or orange, with segments III and IV often darker than basal two segments ( Fig. 1 ); prothorax and scutellum blackish and shiny ( Fig. 1 ); humeral angles strongly prominent posteriad ( Fig. 1 ); scutellum with Y-shaped carina; hemelytra not exceeding apex of abdomen ( Fig. 1 ); femora and tibiae pale orange to brownish yellow ( Fig. 1 ); tibiae without dark annulations ( Fig. 1 ); paramere strongly curved throughout its length, with projection at base ( Fig. 9 ); and ovipositor more than 1.0 mm, nearly reaching sternite IV in rest ( Fig. 5 ). Body length 4.25–5.55 mm in length.

Description of genitalia. Male: Pygophore ( Fig. 8 ) nearly globe-like in dorsal view, covered with suberect setae in apical half; dorsal aperture wide, more than one-third as wide at middle as pygophore, with collar along anterior margin. Paramere ( Fig. 9 ) strongly curved in apical two-thirds, covered with several short to long, erect setae in basal one-third, and with projection near base. Phallosoma ( Figs. 10, 11 ) twice as long as its width in ventral view. Endosoma ( Figs. 12, 13 ) a little twisted in apical part, lacking definite sclerotized processes.

Females: Ovipositor ( Fig. 5 ) 1.38–1.60 mm in length, nearly reaching sternite IV in rest. Spermatheca ( Fig. 14 ) almost globe, with rounded lobe near apex.

Distribution. Japan: Honshu, Shodoshima, Shikoku, Kyushu.

Remarks. In addition to the characters in the key mentioned above, this species is separable from other Japanese congeners of Sadoletus by having an almost concolorous antenna, legs, and abdomen; the hemelytra not exceeding the apex of the abdomen; and the female abdominal sternites V and VI with the posterior margins strongly curved anteriad.

This species is more similar in the male and female genital structures to species of other heterogastrid genera such as Parathyginus Scudder and Heterogaster Schilling than to other Japanese members of Sadoletus (cf. Servadei 1951; our observation). It may suggest that a taxonomic revision of Sadoletus with a careful examination of all the species of this genus is needed.

Biological notes. According to Miyoshi (1997), this species was collected from Alnus sieboldiana Matsumura (Betulaceae) . In addition, Platycarya strobilacea Sieb. et Zucc. (Juglandaceae) was also confirmed as a new host plant of this heterogastrid by our field research in Yamaguchi, western Honshu. A number of adults and nymphs, often hiding in chinks of the cone-like nuts, were collected from the trees.

Sadoletus ryukyuensis Ban et Ishikawa, sp. nov. ( Figs. 2–3 , 6 , 15–22 )

Sadoletus valdezi (non Bergroth, 1918): Hidaka, 1959: 200; Miyamoto and Yasunaga, 1989: 175; Tomokuni, 1989: 191; Hayashi, 2002: 141.

Type series. Holotype: 3, Shirahama, Iriomote-jima Is., the Ryukyus, 13.V.2008, TB (TUA). Paratypes: 39 3 34 Ƥ — the Ryukyus [Yaku-shima Is.] 1 3, Hirauchi, 25.V.1960, Y. Kimura (OMNH). [Tokara Islands] 1 Ƥ, Nakanoshima Is., 13.VI.1953, T. Nakane (ELKU). [Tokuno-shima Is.] 5 3 3 Ƥ, Matsubara, Amagi-chô, 2.X.1988, M. Tomokuni (NSMT). [Okinawa Is.] 1 Ƥ, Matsuda, Ginoza-son, 4–8.V.1995, M. Sugimoto (TUA). [Miyako-jima Is.] 1 Ƥ, Higashi-sokobaru, Hirara, 30.X.1999, light trap, TI (TUA). [Ishigaki-jima Is.] 2 3, Kabira, 15.VI.1966, S. Tachikawa (TUA); 1 3 2 Ƥ, Banna Park, 25.III.1997, H. Yoshitake (TUA); 1 Ƥ, Sokobaru, 24.V.2000, TI (TUA); 1 3, Tomino, 27.IX.2002, H. Yamamoto (ICMI); 1 Ƥ, Omoto, 1.X.2002, light trap, H. Yamamoto (ICMI); 1 3, Mt. Omoto-dake, 4.VI.2003, S. Nagashima (ICMI). [Kuro-shima Is.] 1 Ƥ, Hori, 28.V.2001, T. Shimada (ICMI). [Iriomote-jima Is.] 7 3 2 Ƥ, Funaura, 12.XI.1984, M. Tomokuni (NSMT); 2 Ƥ, Toyohara, 10–11.V.1997, TI (TUA); 14 3 2 Ƥ, Komi, 21.VI.1998, light trap, TI (TUA); 1 3, Shirahama-rindo, 21.XI.1998, TI (TUA); 1 Ƥ, Shirahama-rindo, 30.V.2000, TI (TUA); 1 3, Shirahama, 23.XI.1998, T. Shimada (TUA); 1 Ƥ, Shirahama, 19.VI.2003, T. Tsuru (TUA); 1 3 2 Ƥ, Shirahama, 12.V.2008, TB (TUA); 2 3, Otomi-rindo, 24.IV.2004, T. Tsuru (TUA); 2 3 4 Ƥ, Otomi, 19.V.2007, TB (TUA). [Yonaguni-jima Is.] 4 Ƥ, Mt. Urabu-dake, 16.XI.1998, TI (TUA); 1 Ƥ, Mt. Urabu-dake, 9.IX.2004, S. Arai (TUA); 4 Ƥ, Tarumai, 9.VI.2005, light trap, TI (TUA).

Diagnosis. Recognized among congeners of Sadoletus by a combination of the following characters: head, anterior lobe of pronotum, and basal half of scutellum blackish ( Figs. 2, 3 ); male antenna brownish yellow in segment I and basal half of segment II and blackish in remaining parts ( Fig. 2 ); posterior lobe of pronotum yellowish brown with pale stripe along meson and often with 4 dark markings arranged transversely near posterior margin ( Figs. 2, 3 ); scutellum with pale stripe along meson in apical half ( Figs. 2, 3 ); hemelytra well surpassing apex of abdomen ( Figs. 2, 3 ); corium blackish in apical one-third to apical half in male ( Fig. 2 ); tibiae with blackish annulations ( Figs. 2, 3 ); laterotergites concolor ( Fig. 15 ); pygophore horizontally elliptical in dorsal view ( Fig. 16 ); paramere narrow, twisted at basal one-third, expanded at apical one-third ( Fig. 17 ); and female abdominal sternite VII with posterior margin roundly projected at both sides of midpoint (cleft on midline). Body length 3.65 to 5.25 mm.

Description. Male (holotype): Venter almost blackish. Setae on body silvery. Punctures on pronotum, scutellum, and coria dark brown. Head ( Fig. 2 ) blackish; clypeus brownish yellow. Antenna ( Fig. 2 ) brownish yellow in segment I and basal half of segment II and blackish in remaining parts. Rostrum pale brown, with segment IV dark brown apically. Pronotum ( Fig. 2 ) blackish in anterior lobe and yellowish brown in posterior lobe, with pale stripe along meson on posterior lobe and 4 dark markings arranged transversely near posterior margin. Area above acetabula and posterior margin of metepisternum brownish. Evaporatrium dark gray; peritreme brownish yellow. Scutellum ( Fig. 2 ) blackish in basal half and brownish in apical half, with pale stripe along meson in apical half. Corium ( Fig. 2 ) whitish in basal two-thirds and blackish in remaining part; clavus whitish; membrane hyaline. Coxae brownish, except apical margin pale yellow; trochanter pale yellow; femora and tibiae brownish yellow, with dark brown annulations; tarsomere I pale yellow, except apical margin dark brown; tarsomeres II and III dark brown. Abdominal sternites VI and VII dark brown at middle; laterotergites ( Fig. 15 ) uniformly dark brown.

Body ( Fig. 2 ) 3.3 times as long as width across humeri, covered with pubescence. Head ( Fig. 2 ) 1.4 times as wide as its length, covered with both rough and fine punctures; tylus tumid upwards; clypeus weakly projecting anteriad; juga with decumbent setae. Eyes large, occupying nearly half area of head in lateral view, not reaching anterior margin of pronotum. Antennae covered with suberect setae; proportional lengths of segments I to IV 1.0: 2.3: 1.8: 2.2. Rostrum attaining to mesocoxae; proportional lengths of segments I to IV 1.6: 1.8: 1.3: 1.0.

Pronotum ( Fig. 2 ) a little more than 1.4 time as wide as its length, nearly trapezoidal, lacking collar, densely covered with punctures, and with lateral margin of anterior lobe weakly serrate; posterior lobe 1.25 times as long as anterior lobe, a little more convex than anterior lobe; posterior margin almost straight. Venter of prothorax, mesepisternum and metepisternum covered with rough punctures. Scutellum ( Fig. 2 ) triangular, weakly tumid transversely in basal half, entirely covered with punctures. Hemelytra ( Fig. 2 ) exceeding apex of abdomen, lacking punctures from outside along vein R+M; apical margin of corium as long as claval suture. Profemur moderately expanded, armed with 2 spines ventrally at about apical one-third; one of these spines large and another small; tibiae covered with long setae, becoming gradually thicker in apical half.

Abdomen ( Fig. 2 ) as wide as hemelytra; venter covered with fine punctures, except sternites VI and VII glabrous and polished medially.

Genital structures of paratypes: Pygophore ( Fig. 16 ) horizontally elliptical in dorsal view, covered with erect and suberect setae; dorsal aperture about one-third as wide at middle as pygophore, lacking collar. Paramere ( Fig. 17 ) narrow, twisted at basal one-third, widened at apical one-third, spatula-shaped in apical part, covered with a few setae. Phallosoma ( Figs. 18, 19 ) 1.5 times as long as its width in ventral view, roundly concave along apical margin; endosoma ( Figs. 20, 21 ) with 2 areas of sclerotized processes; basal one of these areas with larger processes than apical one.

Females (paratypes): resembles male in general appearance ( Fig. 3 ). Body evidently wider; antennae paler; coria entirely whitish to brownish yellow ( Fig. 3 ); annulations on femora paler; abdomen obviously wider than hemelytra ( Fig. 3 ); abdominal sternite VII with posterior margin roundly projected at both sides of midpoint (cleft on midline) ( Fig. 6 ); ovipositor 0.55 to 0.75 mm in length, nearly reaching sternite VI ( Fig. 6 ); spermatheca narrow, turned upwards at apex ( Fig. 22 ).

Variations: body length varies from 3.65 to 5.25 mm. Blackish parts of the pronotum, scutellum, and coria are also variable in area.

Measurements (holotype). Body length 4.76 (paratypes 3.65–5.25), width 1.43; head length 0.80, width across eyes 1.13; lengths of antennal segments I, II, III and IV 0.31, 0.70, 0.56 and 0.68, respectively; lengths of rostral segments I, II, III and IV 0.63, 0.71, 0.50 and 0.40, respectively; pronotum length 1.00, width 1.43; hemelytron length 3.06; scutellum length 0.80, width 0.78.

Distribution. Japan: the Ryukyus (Yaku-shima Is., Nakano-shima Is., Tokuno-shima Is., Okinawa-honto Is., Miyako-jima Is., Ishigaki-jima Is., Kuro-shima Is., Iriomote-jima Is., Yonaguni-jima Is.).

Etymology. Named after the Ryukyus, an archipelago lying between Kyushu and Taiwan, the distributional range of this new species; an adjective.

Remarks. This new species is most similar in general appearance to S. valdezi Bergroth. However , it can be distinguished from the latter by a combination of the following characters: head and antennae darker, laterotergites uniformly dark brown, apical one-third of corium blackish in male, and posterior margin of female abdominal sternite VII roundly projected at both sides of midpoint. Male of this new species resembles in general habitus S. corvus Distant, S. barkei Bergroth, and S. voluptarius Bergroth, but it can be distinguished from the latter three species by the antennae being brownish yellow in segment I and basal half of segment II and blackish apically, the brownish yellow femora with dark brown annulations, and the smaller blackish areas of the coria.

Hidaka (1959) first reported this species as S. valdezi Bergroth from Japan on the basis of four specimens (one male and two females from Nakano-shima Island and one male from Ishigaki-jima Island). Of these specimens, one female (Nakano-shima Is.) examined in this present study and another specimen shown in Hidaka’s paper (1959, Fig. 2 ) (apparently male; locality not indicated) belongs to S. ryukyuensis sp. nov. without doubt. Although, unfortunately, the other two specimens (one male and one female) were not located by us, they are strongly supposed to be identical with this new species because the male has definite coloration in the hemelytron which is much different from that of S. valdezi , and all of the females were collected from the same locality (Nakano-shima Is.), which is far from the distributional range of S. valdezi .

Biological notes. A number of adults of S. ryukyuensis sp. nov. was collected from trees of Ficus virgata Reinw. ex Blume (Moraceae) bearing a number of fruits, which may be a host plant of this new species. The new species is often attracted by artificial light.

Figures

FIGURES 1 – 4. Habitus of Japanese Sadoletus. 1, S. izzardi, male; 2 – 3, S. ryukyuensis sp. nov., male (2) and female (3); 4, S. valdezi, male. Scales: 1.0 mm.

FIGURES 5 – 7. Apical part of female abdomen, ventral view. 5, Sadoletus izzardi; 6, S. ryukyuensis sp. nov.; 7, S. valdezi. Scales: 0.5 mm. abbreviations: st 7, sternite VII.

FIGURES 8 – 14. Sadoletus izzardi. 8, Pygophore, dorsal view (setae omitted from left half); 9, left paramere, dorsal view; 10 – 11, phallus (endosoma not everted), ventral (10) and lateral (11) views; 12 – 13, phallus (endosoma everted), ventral (12) and lateral (13) views; 14, spermatheca. Scales: 0.1 mm.

FIGURES 15 – 22. Sadoletus ryukyuensis sp. nov. 15, Laterotergites, dorsal view; 16, pygophore, dorsal view (setae omitted from left half); 17, left paramere, dorsal view; 18 – 19, phallus (endosoma not everted), ventral (18) and lateral (19) views; 20 – 21, phallus (endosoma everted), ventral (20) and lateral (21) views; 22, spermatheca. Scales: 0.5 mm for Fig. 15, 0.1 mm for Figs. 16 – 22.