Pherolepis hizenicus, 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 : 35-37

Pherolepis hizenicus n. sp.

( Figs 6 D–G, 13, 20E–O)

Type material. Holotype (♂). JAPAN: Kyushu, Saga Pref., Saga City, Kinryu Town, 33.30, 130.30, Salix sp. (prob. S. pierotii Miq. ), 23 Jul 2020, NWHS Biol. Club. ( NIAES) ( AMNH _PBI 00380680). Paratypes. Same data as for holotype, 15 ♂, 18 ♀ ( AMNH, CNC, TYCN); same data, 4th instar nymph when collected, developing into 5th on 25 Jul, emerging on 30 Jul, 1 ♂ ( TYCN).

Diagnosis. Recognized primarily by its rather small size; chestnut brown general coloration; fuscous head, pronotum and scutellum; somber yellow antennal segments II and III; brown hemelytron usually often with reddish or yellowish lateral margins; somber yellow femora that are sometimes weakly obscured; elongate, spatula-shaped sensory lobe of left paramere; and well-developed, distinctly spinulate median process of endosoma. Most closely related to Ph. amplus Kulik, 1968 , known from eastern continental Asia including Korean Peninsula, Ph. hizenicus n. sp. can be distinguished by above diagnostic characters.

Description. Body generally chestnut brown, partly tinged with red in fresh specimens ( Fig. 6D ), elongateovoid in overall appearance, not constricted laterally ( Fig. 6F ); dorsal surface with uniformly distributed, simple, reclining setae and silvery sericeous setae on head, dorsum and thoracic pleura. Head dark brown; head with eyes (1.3–1.4 times) wider than high; vertex relatively wide. Antenna somber yellowish brown; extreme apices of segments I and II sometimes darkened; segment II weakly clavate; segments III and IV grayish brown. Labium shiny chestnut brown, partly reddish, reaching subapical part of metacoxa. Pronotum shiny fuscous, with sparsely distributed sericeous setae anteriorly (or calli area); scutellum fuscous, shallowly and transversely rugose, with sparsely distributed sericeous setae; pleura shiny dark brown, partly tinged with red; scent efferent system smoky reddish brown, triangular, with rather small peritreme ( Fig. 20H ). Hemelytron brown, somewhat matte; exocorium sometimes yellowish or reddish brown; membrane smoky brown, semitransparent laterally, with yellowish veins. All coxae creamy yellow, with reddish extreme bases ( Fig. 6E ); legs somber yellow; each femur sometimes weakly obscured but not distinctly darkened; apical part of tarsomere III brown; pretarsal structure as in Fig. 20I . Abdomen shiny fuscous, with ventral median part often reddish brown in both sexes. Male genitalia ( Figs 13 A–B, 20J–L): Genital segment rather small, trapezoidal; phallotheca broad with a tapered apex ( Fig. 20J ); left paramere sprayedout, with developed, spatula-shaped sensory lobe ( Fig. 20K ); right paramere rather bulbous, with small hypophysis ( Fig. 13A ). Endosoma C-shaped, with developed, distinctly spinulate median process ( Figs 13B , 20L ). Female genitalia ( Figs 13 C–D, 20M–O): Genital chamber with laterally thickened and folded sclerotized rings and narrow, concentric sclerites ( Fig. 20M ); interramal lobe of posterior wall widely spinulate except for basal (anterior) margin ( Fig. 20N ).

Measurements. ♂/ ♀ (n=5 each): Total body length 3.1̅3.6 (mean 3.30)/ 3.4̅3.9 (3.60); head height 0.61̅0.65 (0.63)/ 0.66̅0.71 (0.68); width of head across eyes 0.85̅0.92 (0.89)/ 0.91̅0.95 (0.93); width of vertex 0.36̅0.42 (0.40)/ 0.43̅0.45 (0.45); lengths of antennal segments I̅IV 0.25̅0.27, 0.78̅0.93, 0.33̅0.39, 0.30–0.38 (0.26, 0.85, 0.35, 0.34)/ 0.25̅0.29, 0.87̅0.90, 0.36̅0.41, 0.34̅0.44 (0.27, 0.89, 0.40, 0.39); basal width of pronotum 1.09–1.25 (1.18)/ 1.21̅1.26 (1.24); maximum width across hemelytron 1.38–1.52 (1.45)/ 1.50̅1.67 (1.61); and length of metafemur, tibia and tarsus 0.90–1.05, 1.38–1.53, 0.32–0.42(1.01, 1.44, 0.36)/ 1.00̅1.19, 1.52̅1.62, 0.33̅0.42 (1.07, 1.58, 0.37).

Etymology. Named for an ancient name of the type locality area (Hizen); Latinized as adjective.

Biology. Both adults and late instar immatures of this new species were found from leaves of a willow, possibly identical to Salix pierotii Miq. (Salicaceae) growing at water margins or marshy environment. In laboratory observation, a fourth instar immature successfully developed into fifth ( Fig. 6G ) then adult male ( Fig. 6D ) in eight days, reared with a diluted fermented milk beverage (but the individual also frequently sucked on the plant tissue, cf. Fig. 6E ). One generation per year is assumed for P. hizenicus ; the adults appear from mid-July to mid-August.

Discussion. The genus Pherolepis is currently composed of eight eastern Palearctic members which predominantly occur in cold temperate climate zone. The majority of the congeners are associated with deciduous broadleaf hosts (e.g., elm, willow), but a Chinese species, Ph. robustus Zhang & Liu , was observed to have fed on buds and needles (leaves) of Pinus sp. in Shandong Prov. ( Zhang & Liu 2009). Therefore, host associations of Pherolepis species are basically similar to those of Pilophorus members.

The present new species were found from warm temperate climate zone in southwestern Japan and is currently considered to be isolated from other congeners. The holotype male of Pherolepis amplus Kulik (deposited in Zoological Institute, Russian Academy of Sciences, St. Petersburg) has the significantly darkened dorsum, antenna and femora, and more shinier pronotum with very sparsely distributed sericeous setae. Based on descriptions of Chinese ( Zhang & Liu 2009) and Korean ( Duwal et al. 2014) specimens, broadly conceived P. amplus most probably contains several cryptic species and needs further verification.

Figures

FIGURE 6. Habitus images of conifer-inhabiting Pilophorus spp. (A–C) and Pherolepis spp. (D–H), live adults and 5th instar nymph (G). A. Pilophorus miyamotoi ♂. B. P. validicornis ♀ (image courtesy of M. Nozawa). C. P. tagoi ♀ (courtesy of M. Nozawa). D. Pherolepis hizenicus n. sp., ♂. E. Same, lateral view. F. Same, ♀. G. Same, 5th instar nymph, ♂. H. Pherolepis fasciatus ♀.

FIGURE 13. Male (A–B) and female (C–D) genitalia of Phelorepis hizenicus n. sp. A. Pygophore with parameres. B. Endosoma (vesica). C. Bursa copulatrix, dorsal view. D. Same, ventral view.

FIGURE 20. Scanning electron micrographs for Pilophorus niger (A–C), P. tagoi (D), and Pherolepis hizenicus n. sp. (E–O). A, D, G. Left lateral habitus. B, I. Metatarsus. Right lateral habitus. C, L. Endosoma. E. Dorsal habitus. F. Left-dorsolateral habitus. H. Thoracic pleura, left lateral view. J. Pygophore, dorsal view. K. Left paramere. M. Bursa copulatrix, dorsal view. N–O. Posterior wall of bursae.