Plautia sakishimensis Ishikawa & Moriya 2019
Creators: name: Ishikawa, Tadashi
name: Moriya, Seiichi
Publisher: name: Zenodo
Year: 2019
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hemiptera
Pentatomidae
Plautia
Plautia sakishimensis

description: Plautia sakishimensis Ishikawa & Moriya, sp. nov.
(Figs. 2, 13, 15, 22–24, 29, 34, 39, 44, 49, 54, 59, 64, 69, 74, 80, 81)
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); antennal segment IV blackish in apical 1/3 or more less (Fig. 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); lateral margins of pronotum blackish (Fig. 22); blackish line of lateral margin of pronotum usually irregularly interrupted (Figs. 23, 24) (sometimes complete, Fig. 22); crown of paramere constricted in apical part (Fig. 44); lateral lobe of crown triangularly extended, with almost straight proximal margin (Fig. 44); conjunctival processes of endosoma expanded laterad, curved ventrad, with a dorsal expansion and a pair of lateral expansions at base (Figs. 49, 54, 59, 64); processes of vesica V-shaped in ventral view, semitrapezoidal in outline in posterior view (Figs. 54, 64); sclerotized zone of intermediate part of spermatheca approximately 1/5 as long as intermediate part (Figs. 80, 81).
Description. Male. Coloration. Body generally yellowish green (Fig. 2). Punctures on pronotum, scutellum and coria generally blackish (Fig. 15). Head with short longitudinal blackish line above anteniferous tubercle (Figs. 22–24). Antennal segments I and II yellowish green (Fig. 13); segment III yellowish green in basal half, yellowish brown from middle to apical 1/5, and blackish in apical 1/5 (Fig. 13); segment IV yellowish brown in basal 7/10 and blackish in apical 3/10 (Fig. 13); segment V yellowish brown in basal half and in apical 1/5, and blackish from middle to apical 1/5 (Fig. 13). Labium brownish yellow, with blackish apical part. Pronotum blackish along lateral margins; blackish line of lateral margin often irregularly interrupted (Fig. 23), sometimes almost disappearing except both ends (Fig. 24), or rarely complete (Fig. 22). Apical part of scutellum yellowish (Figs. 2, 15). Corium of fore wing except antero-marginal area brown to dark brown, sometimes with a few pale irregular markings (Figs. 2, 15); membrane of forewing transparent, tinged with pale brown (Fig. 2). 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). Labium reaching abdominal segment III; approximate proportion of segments I to IV 1.0: 1.8: 1.4: 1.2.
Pronotum (Fig. 15) 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); 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) 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); punctures of coria denser than and almost same in size as punctures of pronotum and scutellum (Fig. 15).
Abdomen (from base of segment III to apex of segment VII) approximately 7/10 as long as its maximum width. Genital capsule (Figs. 34, 39) 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, 34) widely concave, slightly sinuate in middle part; concavity of ventral rim approximately 1/6 as deep as its maximum width (Fig. 34); transverse ridge well developed, invisible in ventral view, with slightly concave dorsal margin in posterior view (Fig. 39); dorsal sclerites semicircular, with acute ventral angle (Fig. 39); inner margin of dorsal sclerite slightly concave throughout its length (Fig. 39); dorsal sinus subpentagonal in posterior view (Fig. 39); paramere sockets subtriangular in posterior view (Fig. 39). Crown of paramere (Fig. 44) 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, 54, 59, 64) 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, 64). Vesica gently curved in lateral view, with distal margin of processes of vesica at same level (Fig. 59). Processes of vesica relatively small, V-shaped in ventral view (Fig. 54), round in lateral view (Fig. 59), semitrapezoidal in outline in posterior view (Fig. 64).
Female. Similar to the male. Body relatively larger than male. Valvifer VIII generally yellowish green, becoming yellowish apicad (Fig. 69), covered with short to long setae along posterior and mesal margins, and with a few setae on disc (Fig. 74); apical angle a little more acute than right angle (Fig. 74). Spermatheca long; apical receptacle (Figs. 80, 81) 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) 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); distal flange as wide as proximal flange (Figs. 80, 81).
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), “[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) [vs. blackish at least in apical 1/3 (Fig. 12)], antennal segment IV blackish in apical 1/3 or more less (Fig. 13) [vs. blackish in apical half (Fig. 12)], a blackish line of the lateral margin of the pronotum usually irregularly interrupted (Figs. 23, 24) [vs. usually complete (Fig. 19)], the lateral lobe of the crown of paramere triangularly extended (Fig. 44) [vs. widely extended laterad, with the edge roundly and deeply concave (Fig. 43)], and the conjunctival processes of endosoma with a dorsal expansion and a pair of lateral expansions at the base (Figs. 49, 54, 59, 64) [vs. lucking such expansions (Figs. 48, 53, 58, 63)]. 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) [vs. slightly carinate], punctures of coria of fore wings denser than and almost same in size as punctures of pronotum and scutellum (Fig. 15) [vs. much denser and larger], the posterior angles of genital capsule round in the dorsal and ventral views (Figs. 29, 34) [vs. angulate], the ventral angle of the dorsal sclerites of genital capsule acutely projected (Fig. 39) [vs. merely angulated], crown of paramere curved upward and constricted in apical part (Fig. 44) [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, 54, 59, 64) [vs. lacking such expansions].
description: Published as part of Ishikawa, Tadashi & Moriya, Seiichi, 2019, A review of the stink bug genus Plautia Stål from Japan (Hemiptera, Heteroptera, Pentatomidae), pp. 470-490 in Zootaxa 4564 (2) on pages 475-478, DOI: 10.11646/zootaxa.4564.2.8, http://zenodo.org/record/2589359