Pilophorus setulosellus, Yasunaga & Duwal & Nakatani, 2020

Yasunaga, Tomohide, Duwal, Ram Keshari & Nakatani, Yukinobu, 2021, Reclassification of the plant bug genus Pilophorus in Japan and key to the genera and species of Japanese Pilophorini (Hemiptera: Heteroptera: Miridae Phylinae), Zootaxa 4942 (1), pp. 1-40 : 25-27

Pilophorus setulosellus n. sp.

( Figs 5E , 11 F–G, 12J–K, 18A–H, 19J–L)

Type material. Holotype (♂). JAPAN: Honshu, Hiroshima Pref., Mt. Ungetsu (Uzutsuki), 900 m alt., 34.80, 132.23, Artemisia sp., 4 Sep 1992, T. Yasunaga ( NIAES) ( AMNH _ PBI 00380676 ) . Paratypes. JAPAN: Honshu: Same data as for holotype, 2 ♂, 3 ♀ ( TYCN) ; Hiroshima Pref., Takiyamakyo , 34.64, 132.30, 28 Jun 1997, collector unknown, 2 ♀ ( TYCN) ; Okayama Pref., Kibi-Hills , 34.8255, 133.7635, Artemisia sp., 30 Aug 2002, T. Yasunaga, 1 ♀ ( TYCN) ; same data except for date 15 Jun 2002, 2 ♂ ( TYCN) ; Okayama Pref., Chuka-son, Hatsuwa , 2 Oct 1992, T. Yasunaga, 2 ♀ ( TYCN) ; Okayama Pref., Hiruzen Plateau , Artemisia sp., 4 Sep 2002, T. Yasunaga, 2 ♀ ( TYCN) ; Okayama Pref., Wake Town, Hara , Yoshii River , 34.794, 134.133, 23 May 1994, Wesco Co., 1 ♀ ( TYCN) ; Tottori Pref., Hino-gun, Nichinan Town , 35.21, 133.31, 12 Jul 1994, Wesco Co., 1 ♀ ( TYCN) . Shikoku : Kochi Pref., Tsuno Town, Tengu Plateau , 33.472, 133.002, Lespedeza sp., 4 Sep 1997, T. Yasunaga, 2 ♀ ( TYCN) (00380677). Additional material. JAPAN: Honshu, Nara Pref., Higashi Yoshino , 34.41, 136.02, 22 May 1992, M. Takai, 1 ♂ ( TYCN) .

Diagnosis. Recognized by its comparatively small size and short appendages( Table2); distinctly setose pronotum and hemelytron with brown, semierect or upright setae, lacking dark stiff seta ( Fig. 5E ); almost straight, continuous median band of scale-like setae; bulbous, small right paramere ( Fig. 18H ); narrow apical ridge of endosoma ( Fig. 11 F–G); and smooth basal (anterior) part of interramal lobe lacking spinule ( Fig. 19J ). Distinguished from most closely related sibling, P. setulosus , by the characters in above key (couplet 12) and the shape of the genitalia as follows: right paramere smaller and more rounded ( Fig. 18H ); shorter branch of endosomal median process more than 1/3 length of longer branch ( Fig. 11 E–F); and posterior wall of bursae narrower, with interramal lobe almost lacking spinules dorsally (or basally) ( Fig. 19J ).

Description. Body generally brown, small in overall appearance, moderately constricted; dorsal surface weakly shining, with uniformly distributed, simple, short, semierect setae and brownish, upright setae. Head shiny fuscous, with uniformly distributed, pale, simple upright setae; head with eyes wider than high; vertex relatively wide, narrowly carinate basally. Antenna dark brown; segment I pale brown; basal 2/3 of segment II reddish brown, rather clavate; basal half of segment III and extreme base of IV creamy yellow. Labium shiny reddish brown, slightly exceeding apex of mesocoxa. Pronotum shiny fuscous; scutellum fuscous, somewhat arched, shallowly wrinkled, with scale-like setae aggregated on each corner; pleura dark brown; propleuron brown; mesepimeron wholly covered with scale-like setae; scent efferent system yellowish brown. Hemelytron brown, matte, with almost straight median band of scale-like setae; lateral part of corium posterior to median band darkened; membrane smoky brown. Coxae pale brown, except for brown mesocoxa; legs chestnut brown; all tibiae and tarsi brown; metatibia slightly curved; tarsomere III brown. Abdomen dark reddish brown, with clustered scale-like setae laterally on sterna III–V. Male genitalia ( Figs 11 F–G, 18E–F): Right paramere small, rounded, with pointed hypophysis; median process of endosoma bifurcate. Female genitalia ( Figs 12 J–K, 19J–L): Sclerotized ring narrowly folded laterally ( Fig. 10 A–B); vestibular sclerite somewhat projected right-laterally thumb-like knob ( Fig. 11J ); spinules on dorsal (basal) part of interramal lobe wanting, or only sparsely distributed ( Fig. 19J ).

Measurements. See Table 2.

Etymology. From the specific name setulosus + a diminutive suffix (-ellus), referring to the evidently smaller size (than setulosus as in Table 2) of this new species.

Biology. Adults of this new species were found from Artemisia herbs or Lespedeza shrubs but immature forms are yet to be confirmed. Collection records suggest that P. setulosellus has a bivoltine life cycle. No other biological information is currently available.

Discussion. This new species corresponds to specimens previously identified as P. setulosus in southwestern Japan; the latter is now recognized to be distributed in northern deciduous forest zones. Therefore, previous records of P. setulosus (cf. Yasunaga, 2001) from southwestern Japan (Shikoku, Kyushu and western Honshu) were most probably confused with P. setulosellus . Each species can be separated unequivocally by the above diagnostic characters, and a preliminary DNA sequencing data also supports the identity of respective species (Nakatani, unpublished data).

Figures

FIGURE 5. Habitus images of Pilophorus spp., live adult individuals. A–B. P. satoyamanus n. sp. ♂ (images courtesy of M. Takai). C–D. P. okamotoi ♂. E. P. setulosellus n. sp. ♀ (courtesy of M. Takai). F. P. setulosus ♀.

FIGURE 10. Male genitalia of Pilophorus spp. A–B. P. hyotan n. sp. (from Tokyo, Japan). C–E. P. typicus (Nagasaki, Japan: C; India: D; Palawan, Philippines: E).

FIGURE 11. Male endosoma (vesica) and endosoma of Japanese Pilophorus spp. A. P. choii (from Otaru). B. P. erraticus (Nagasaki). C. P. pseudoperplexus (Kanagawa). D. P.okamotoi (Tsushima Is.). E. P.satoyamanus n. sp. (Kochi).F. P.setulosellus n. sp. (Hiroshima). G. Same (Nara). H. P. setulosus (Sapporo, type locality, Salix). I. Same, (Shiretoko, Artemisia).

FIGURE 12. Female bursa copulatrix and eggs (B, E, H) of Japanese Pilophorus spp. A, C, F, K–L. Dorsal view. D, G, I, J, M. Ventral view, with vestibular sclerite (VES). A–B. P. erraticus (Nagasaki). C–E. P. pseudoperplexus (Otaru). F–H. P. satoyamanus n. sp. (Ibaraki). I. P. okamotoi (Tsushima Is.). J–K. P. setulosellus n. sp. (Hiroshima). L–M. P. setulosus (Asahikawa).

FIGURE 18. Scanning electron micrographs for Pilophorus setulosellus n. sp. (with black circles●) and P. setulosus. A. Right dorsolateral habitus. B. Right lateral habitus. C, K. Ventral habitus. D. Thoracic pleura, left lateral view. E, L. Pygophore, dorsal view. Scutellum. F, M. Endosoma. G, O. Metatarsus. H, N. Right paramere. I. Dorsal habitus. J. Left lateral habitus.

FIGURE 19. Scanning electron micrographs of female genitalia for Pilophorus spp.. A–C. Pilophorus okamotoi. D–F. P. satoyamanus n. sp. G–I. P. pseudoperplexus. J–L. P. setulosellus n. sp. M–O. P. setulosus. A–B, D–E, G–H, J–K, M–N. Posterior wall of bursae. C, F. Ovipositor (gonapophysis II). I, L, O. Bursa copulatrix, ventral view.