Pityopsallus Wagner, 1952

Yasunaga, Tomohide, 2022, The plant bug subfamily Phylinae in Japan, with key to genera and descriptions of eight new species (Hemiptera: Heteroptera: Miridae), Zootaxa 5094 (1), pp. 1-52 : 22-24

Genus Pityopsallus Wagner, 1952

Diagnosis: Pityopsallus is distinguished from other phyline genera by the following characters, some of which (underlined) are hypothesized as autapomorphies: Dorsal silvery setae slender, almost as thick as simple setae ( Figs. 26H, O ; 28B ); labium thick, its apex sometimes reaching genital segment ( Fig. 26M ); metathoracic scent efferent system comparatively small ( Fig. 26I, N ); left paramere remarkably elongate, covering (or conforming to) apical part of phallotheca ( Fig. 28 C−D, G−L); vesica J-shaped, composed of 4–5 strap-like sclerites that are strongly twisted subapically (12C−E), usually with wide apical plate ( Fig. 28F ); apical blade of vesica tapered, notched ( Fig. 27D ); secondary gonopore completely circular, thick-rimmed ( Fig. 27E ); bursa copulatrix with weak, reduced sclerotized rings; interramal lobe of posterior wall narrow, covered with spinulate scale-like microstructures ( Fig. 27K, N ); interramal sclerite with relatively densely distributed, comb-like scaly microstructure ( Fig. 27L, O ); and ovipositor (gonapophysis I) generally slender, relatively rounded apically ( Fig. 12 G−H).

Discussion. Pityopsallus Wagner, 1952 (type species: Psallus luridus Reuter, 1878 , Palearctic) was proposed as a subgenus of the large Holarctic genus Psallus Fieber, 1858 and currently includes seventeen species. As discussed by Wyniger (2018) and evidenced by some plausible autapomorphies assumed in the above diagnosis, Pityopsallus is best regarded as full genus, and the relationship with Psallus is now posited to be only superficial.

Accordingly, the following eight new combinations are proposed for Asian (and E. Siberian) taxa; all are transferred from Psallus Fieber : Pityopsallus ermolenkoi (Kerzhner, 1979) n. comb., Pt. hani (Zheng & Li, 1990) n. comb., Pt. kimi (Josifov, 1983) n. comb., Pt. laricinus (Vinokurov, 1982) n. comb., Pt. laticeps (Reuter, 1878) n. comb., Pt. nipponicus ( Vinokurov, 1998) n. comb., Pt. sachaensis ( Vinokurov, 1998) n. comb., Pt. yasunagai ( Vinokurov, 1998) n. comb.. A continental Chinese species listed as Psallus (Pityopsallus) fortis Li & Liu in Aukema (2018) should be excluded from Pityopsallus and placed in the subgenus Hylopsallus (see below), based on the original description, and figured male genitalia ( Li & Liu, 2007).

Within the Pityopsallus congeners, two monophyletic species-groups are recognized. The first group of species, including the type species of the genus P. luridus , is characterized by the moderate size, long labium whose apex exceeds the metacoxa and sometimes reaches the genital segment ( Fig. 21M ), the elongate and broadened left paramere ( Fig. 28C, D, H , I−L), and the presence of the wide subapical plate on the vesica ( Fig. 28F ). The species of the second group share the relatively small size, shorter labium that is not exceeding apex of metacoxa ( Fig. 26N ), narrowed, caudally pointed left paramere ( Figs. 12A , 28 J−K), and reduced subapical plate on the vesica ( Figs. 12 C−E, 27C−D, I).

Almost all the members of Pityopsallus are associated with Pinaceae conifers ( Yasunaga, 2001d; Wyniger, 2004); however, P. kimi (Josifov, 1983) is known to inhabit willows ( Salix spp. , Salicaceae ) ( Kerzhner 1988; Vinokurov, 1998) and P. hani was found from wheat ( Triticum sp. , Poaceae ) and Pyrus sp. (Rosaceae) . In Japan, six conifer inhabiting Pityopsallus members, including two undescribed species, have hitherto been recognized. The following key would be useful to identify the Japanese congeners.

Key to Japanese species of Pityopsallus

1. Labium very long, its apex easily surpassing apex of metacoxa, reaching abdominal sterna VII–IX (cf. Fig. 26M ); metatarsomere III as long as or slightly longer than I+II; sensory lobe of left paramere conspicuously developed, protruding posteriad (cf. Fig. 28 C−D)...................................................................................... 2

– Apex of labium not exceeding apex of metacoxa; meta-tarsomere III shorter than I+II; left paramere moderately or sharply protruding posteriad ( Fig. 28 J−K)........................................................................ 4

2. Meso and metafemur with clear, fuscous, large spots ventrally; restricted to Abies spp. .................... P. nipponicus

– Ventral spots on meso and metafemur small and obscure; on other conifers....................................... 3

3. Dorsum generally dark brown; ventral surface of metafemur with a row of small, obscure spots mesially; on Pinus pumila at alpine zones in Hokkaido ..................................................................... P. ermolenkoi

– Dorsum somber pale brown to brown; ventral surface of metafemur with obscure spots only on apical region; on Larix kaempferi .................................................................................. P. yasunagai

4. Vertex narrow (0.36 times as wide as head across eyes); labium shorter than basal width of pronotum (currently known only by a male holotype specimen)................................................................. P. sakuraii n. sp.

– Male vertex wider (> 0.38 times as wide as head across eyes); labium about as long as or longer than basal width of pronotum ................................................................................................... 5

5. Metatibia almost equal in length to basal width of pronotum; each claw smooth; in Japan currently known only from Chishima Islands (Kunashiri and Etorofu)................................................................... P. vittatus

– Metatibia longer than basal width of pronotum; claws of pro- and metalegs minutely notched ( Fig. 26D, F ); central and northern Honshu (Nagano and Tochigi).............................................................. P. maeharai n. sp .

Figures

FIGURE 12. Male (A−E) and female (F−I) genitalia of Pityopsallus spp. A−C, F−G. P. maeharai. D. P. sakuraii n. sp. E, H−I. P. vittatus (From Yakutia, Russia). A. Left paramere. B. Right paramere. C−E. Vesica (endosoma). F & I. Bursa copulatrix, ventral view. G−I. Apex of ovipositor (gonapophysis I). Scale bar 0.2 mm.

FIGURE 21. Scanning electron micrographs for Europiella isodonicola n. sp. (A−F), E. miyamotoi (G−L), E. lividella (M−N) and E. senjoensis (O). A, G, M. Left lateral habitus. B, H. Head, dorsal view. C, I. Thoracic pleura, left lateral view. D, J. Metafemur, ventral view. E−F, K−L. Metatarsus. N. Male genital segment. O. Corium.

FIGURE 26. Scanning electron micrographs for Pityopsallus maeharai n. sp. (A−F), P. sakuraii n. sp. (G−L), P. nipponicus (Vinokurov) (M) and P. vittatus (N−O). A, M−N. Left lateral habitus. B, H, O. Dorsal vestiture pattern. D. Protarsus. E, J. Mesotarsus. F, L. Metatarsus. G. Dorsal habitus. I. Thoracic pleura, left lateral view.

FIGURE 27. Scanning electron micrographs for male (A−I) and female (J−O) genitalia of Pityopsallus maeharai n. sp. (A−E, J−L), P. sakuraii n. sp. (F−G) and P. vittatus (M−O). A, F, H. Genital segment (pygophore). B. Right paramere. C−D, G−I. Vesica. E. Secondary gonopore. J−O. Posterior wall.

FIGURE 28. Scanning electron micrographs for Pityopsallus luridus from Yakutia, Russia (A−C), P. yasunagai (Vinokurov) (D–F, O), P. ermolenkoi (Kerzhner) (G–I, M), P. sakuraii n. sp. (J), P. vittatus (K, N) and P. nipponicus (Vinokurov) (L). A. Anterior body, dorsolateral view. B. Vestiture pattern on scutellum and anterior hemelytron. C–D, G–L. Male genital segment (pygophore), left lateral view. E. Same, caudal view. F. Apex of vesica. M–O. Pretarsal structure of metatarsus.