Plautia sakishimensis, Ishikawa & Moriya, 2019

Ishikawa, Tadashi & Moriya, Seiichi, 2019, A review of the stink bug genus Plautia Stål from Japan (Hemiptera, Heteroptera, Pentatomidae), Zootaxa 4564 (2), pp. 470-490 : 475-478

publication ID	https://doi.org/ 10.11646/zootaxa.4564.2.8
publication LSID	lsid:zoobank.org:pub:171E7B4D-773A-4A16-8C0F-3D23F6947A
DOI	https://doi.org/10.5281/zenodo.5922542
persistent identifier	https://treatment.plazi.org/id/03A687D8-FFDD-FFD8-E69C-9510FEADFC19
treatment provided by	Plazi
scientific name	Plautia sakishimensis
status

Treatment

Plautia sakishimensis Ishikawa & Moriya, sp. nov.

( Figs. 2 View FIGURES 1–5 , 13 View FIGURES 12–13 , 15 View FIGURES 14–18 , 22–24 View FIGURES 19–27 , 29 View FIGURES 28–32 , 34 View FIGURES 33–37 , 39 View FIGURES 38–42 , 44 View FIGURES 43–47 , 49 View FIGURES 48–52 , 54 View FIGURES 53–57 , 59 View FIGURES 58–62 , 64 View FIGURES 63–67 , 69 View FIGURES 68–72 , 74 View FIGURES 73–77 , 80, 81 View FIGURES 78–84 )

Diagnosis. Among the species of Plautia , this pentatomid is recognized by the following combination of characters: body 8.4–12.0 mm long; antennal segment III blackish in apical 1/5 ( Fig. 13 View FIGURES 12–13 ); antennal segment IV blackish in apical 1/3 or more less ( Fig. 13 View FIGURES 12–13 ); punctures on disc of pronotum and scutellum blackish and strong, almost same in size and color as punctures on coria of fore wings ( Fig. 15 View FIGURES 14–18 ); lateral margins of pronotum blackish ( Fig. 22 View FIGURES 19–27 ); blackish line of lateral margin of pronotum usually irregularly interrupted ( Figs. 23, 24 View FIGURES 19–27 ) (sometimes complete, Fig. 22 View FIGURES 19–27 ); crown of paramere constricted in apical part ( Fig. 44 View FIGURES 43–47 ); lateral lobe of crown triangularly extended, with almost straight proximal margin ( Fig. 44 View FIGURES 43–47 ); conjunctival processes of endosoma expanded laterad, curved ventrad, with a dorsal expansion and a pair of lateral expansions at base ( Figs. 49 View FIGURES 48–52 , 54 View FIGURES 53–57 , 59 View FIGURES 58–62 , 64 View FIGURES 63–67 ); processes of vesica V-shaped in ventral view, semitrapezoidal in outline in posterior view ( Figs. 54 View FIGURES 53–57 , 64 View FIGURES 63–67 ); sclerotized zone of intermediate part of spermatheca approximately 1/5 as long as intermediate part ( Figs. 80, 81 View FIGURES 78–84 ).

Description. Male. Coloration. Body generally yellowish green ( Fig. 2 View FIGURES 1–5 ). Punctures on pronotum, scutellum and coria generally blackish ( Fig. 15 View FIGURES 14–18 ). Head with short longitudinal blackish line above anteniferous tubercle ( Figs. 22–24 View FIGURES 19–27 ). Antennal segments I and II yellowish green ( Fig. 13 View FIGURES 12–13 ); segment III yellowish green in basal half, yellowish brown from middle to apical 1/5, and blackish in apical 1/5 ( Fig. 13 View FIGURES 12–13 ); segment IV yellowish brown in basal 7/10 and blackish in apical 3/10 ( Fig. 13 View FIGURES 12–13 ); segment V yellowish brown in basal half and in apical 1/5, and blackish from middle to apical 1/5 ( Fig. 13 View FIGURES 12–13 ). Labium brownish yellow, with blackish apical part. Pronotum blackish along lateral margins; blackish line of lateral margin often irregularly interrupted ( Fig. 23 View FIGURES 19–27 ), sometimes almost disappearing except both ends ( Fig. 24 View FIGURES 19–27 ), or rarely complete ( Fig. 22 View FIGURES 19–27 ). Apical part of scutellum yellowish ( Figs. 2 View FIGURES 1–5 , 15 View FIGURES 14–18 ). Corium of fore wing except antero-marginal area brown to dark brown, sometimes with a few pale irregular markings ( Figs. 2 View FIGURES 1–5 , 15 View FIGURES 14–18 ); membrane of forewing transparent, tinged with pale brown ( Fig. 2 View FIGURES 1–5 ). Legs yellowish green; tarsi brownish yellow, darkened at apex of each tarsomere; claws brownish yellow in basal half and black in apical half; pulvilli dark brown. Posterolateral corners of abdominal segments III to VII narrowly and distinctly black.

Structure. Head finely punctate, weakly and densely rugose, approximately 3/4 as long as width across eyes; interocular space approximately 2.8 times as wide as eye in dorsal view. Bucculae roundly convex ventrad in anterior 1/3, pointed at anterior 1/4, gradually tapering posteriad in posterior 2/3. Antenna a little more than 3/5 as long as body length (to apex of abdomen), sparsely covered with short, erect and suberect setae in segments I, II and basal half of segment III, and densely in segments IV, V and apical half of segment III; approximate proportion of segments I to V 1.0: 1.8: 2.1: 2.8: 2.8 ( Fig. 13 View FIGURES 12–13 ). Labium reaching abdominal segment III; approximate proportion of segments I to IV 1.0: 1.8: 1.4: 1.2.

Pronotum ( Fig. 15 View FIGURES 14–18 ) along midline approximately 1.2 times as long as head, approximately 1/3 as long as humeral width; disc of pronotum densely punctate; these punctures distinct and strong ( Fig. 15 View FIGURES 14–18 ); width across humeri approximately 2.4 times as much as width across eyes; humeral angle round, slightly projected laterad; lateral margin straight, smooth, ecarinate, with sparse fine setae. Scutellum ( Fig. 15 View FIGURES 14–18 ) as long as its basal width, punctate as in pronotum. Fore wings exceeding apex of abdominal segment VII by approximately 3/20 of its length ( Fig. 2 View FIGURES 1–5 ); punctures of coria denser than and almost same in size as punctures of pronotum and scutellum ( Fig. 15 View FIGURES 14–18 ).

Abdomen (from base of segment III to apex of segment VII) approximately 7/10 as long as its maximum width. Genital capsule ( Figs. 34 View FIGURES 33–37 , 39 View FIGURES 38–42 ) approximately 2.2 times as wide at maximum as its basal width, approximately 4/5 as long as its maximum width, roundly produced at posterior angles; ventral rim ( Figs. 29 View FIGURES 28–32 , 34 View FIGURES 33–37 ) widely concave, slightly sinuate in middle part; concavity of ventral rim approximately 1/6 as deep as its maximum width ( Fig. 34 View FIGURES 33–37 ); transverse ridge well developed, invisible in ventral view, with slightly concave dorsal margin in posterior view ( Fig. 39 View FIGURES 38–42 ); dorsal sclerites semicircular, with acute ventral angle ( Fig. 39 View FIGURES 38–42 ); inner margin of dorsal sclerite slightly concave throughout its length ( Fig. 39 View FIGURES 38–42 ); dorsal sinus subpentagonal in posterior view ( Fig. 39 View FIGURES 38–42 ); paramere sockets subtriangular in posterior view ( Fig. 39 View FIGURES 38–42 ). Crown of paramere ( Fig. 44 View FIGURES 43–47 ) subtriangular, curved upward and constricted in apical part, round at apex, covered with short to long, erect setae on lateral lobe; inner margin slightly arched; distal margin almost straight, strongly curved near apex of crown; proximal margin almost straight; lateral lobe triangularly extended, round at angle. Conjunctival processes of endosoma ( Figs. 49 View FIGURES 48–52 , 54 View FIGURES 53–57 , 59 View FIGURES 58–62 , 64 View FIGURES 63–67 ) large, well expanded laterally, curved ventrad, provided with large dorsal expansion and a pair of small lateral expansions at base; apices of conjunctival processes weakly sclerotized ( Figs. 54 View FIGURES 53–57 , 64 View FIGURES 63–67 ). Vesica gently curved in lateral view, with distal margin of processes of vesica at same level ( Fig. 59 View FIGURES 58–62 ). Processes of vesica relatively small, V-shaped in ventral view ( Fig. 54 View FIGURES 53–57 ), round in lateral view ( Fig. 59 View FIGURES 58–62 ), semitrapezoidal in outline in posterior view ( Fig. 64 View FIGURES 63–67 ).

Female. Similar to the male. Body relatively larger than male. Valvifer VIII generally yellowish green, becoming yellowish apicad ( Fig. 69 View FIGURES 68–72 ), covered with short to long setae along posterior and mesal margins, and with a few setae on disc ( Fig. 74 View FIGURES 73–77 ); apical angle a little more acute than right angle ( Fig. 74 View FIGURES 73–77 ). Spermatheca long; apical receptacle ( Figs. 80, 81 View FIGURES 78–84 ) spherical, with 1 horn-shaped process; horn-shaped process produced laterad of apical receptacle, abruptly curved basad, surpassing distal flange; intermediate part ( Figs. 80, 81 View FIGURES 78–84 ) nearly parallel-sided, approximately 3.5 times as long as its width at middle, with sclerotized zone apically; apical sclerotized zone of intermediate part approximately 1/5 as long as intermediate part ( Figs. 80, 81 View FIGURES 78–84 ); distal flange as wide as proximal flange ( Figs. 80, 81 View FIGURES 78–84 ).

Measurements [in mm, ♂ (n=79) / ♀ (n=90). Body length 8.4–11.2 (holotype 10.3) / 8.6–12.0; width across eyes 2.3–2.9 / 2.4–3.0; width across humeral width 5.3–6.8 / 5.4–7.4; maximum width of abdomen 5.4–6.8 / 5.2– 7.3.

Type series. Holotype: ♂ ( Fig. 2 View FIGURES 1–5 ), “[ JAPAN] Banna-kôen, Ishigaki-jima Is., the Ryukyus, 19. III. 2012, LT, T. Ishikawa ” (LETUA IC 2018-00133) ( TUA).

A total of 168 paratypes (78♂ 90♀, LETUA IC 2018-00134–00301, TUA) are here designated from the following localities: Miyako-jima Is., Irabu-jima Is., Ishigaki-jima Is., Kohama-jima Is., Iriomote-jima Is., and Yonaguni-jima Is. of the Ryukyu Islands, Japan.

Distribution. The Sakishima Islands, the south-westernmost group of islands within the Ryukyu Islands, Japan.

Etymology. The specific epithet refers to its occurrence in the Sakishima Islands of the Ryukyu Islands, Japan; an adjective.

Remarks. This new species has historically been recognized as the Sakishima Islands population of Plautia stali . We describe this population as a distinct species as mentioned above due to significant differences in external morphology between the Sakishima Islands population and the remaining populations of Plautia stali .

In general appearance, Plautia sakishimensis sp. nov. closely resembles P. stali Scott, 1874 . However, P. sakishimensis sp. nov. is distinguished from P. stali by antennal segment III blackish in apical 1/5 ( Fig. 13 View FIGURES 12–13 ) [vs. blackish at least in apical 1/3 ( Fig. 12 View FIGURES 12–13 )], antennal segment IV blackish in apical 1/3 or more less ( Fig. 13 View FIGURES 12–13 ) [vs. blackish in apical half ( Fig. 12 View FIGURES 12–13 )], a blackish line of the lateral margin of the pronotum usually irregularly interrupted ( Figs. 23, 24 View FIGURES 19–27 ) [vs. usually complete ( Fig. 19 View FIGURES 19–27 )], the lateral lobe of the crown of paramere triangularly extended ( Fig. 44 View FIGURES 43–47 ) [vs. widely extended laterad, with the edge roundly and deeply concave ( Fig. 43 View FIGURES 43–47 )], and the conjunctival processes of endosoma with a dorsal expansion and a pair of lateral expansions at the base ( Figs. 49 View FIGURES 48–52 , 54 View FIGURES 53–57 , 59 View FIGURES 58–62 , 64 View FIGURES 63–67 ) [vs. lucking such expansions ( Figs. 48 View FIGURES 48–52 , 53 View FIGURES 53–57 , 58 View FIGURES 58–62 , 63 View FIGURES 63–67 )]. Moreover, P. sakishimensis sp. nov. is also similar in general appearance to P. crossota (Dallas, 1851) , but is distinguished from the latter by the lateral margins of pronotum not carinate ( Fig. 15 View FIGURES 14–18 ) [vs. slightly carinate], punctures of coria of fore wings denser than and almost same in size as punctures of pronotum and scutellum ( Fig. 15 View FIGURES 14–18 ) [vs. much denser and larger], the posterior angles of genital capsule round in the dorsal and ventral views ( Figs. 29 View FIGURES 28–32 , 34 View FIGURES 33–37 ) [vs. angulate], the ventral angle of the dorsal sclerites of genital capsule acutely projected ( Fig. 39 View FIGURES 38–42 ) [vs. merely angulated], crown of paramere curved upward and constricted in apical part ( Fig. 44 View FIGURES 43–47 ) [vs. not curved and constricted], and conjunctival processes of endosoma with a large dorsal expansion and a pair of small lateral expansions at the base ( Figs. 49 View FIGURES 48–52 , 54 View FIGURES 53–57 , 59 View FIGURES 58–62 , 64 View FIGURES 63–67 ) [vs. lacking such expansions].