Sejanus epicurus, Yasunaga & Duwal, 2022

Yasunaga, Tomohide & Duwal, Ram Keshari, 2022, Two new unique hibiscus-inhabiting species of the plant bug genus Sejanus Distant from Japan and Taiwan (Hemiptera: Heteroptera: Miridae: Phylinae), Zootaxa 5222 (2), pp. 155-167 : 158-162

publication ID	https://doi.org/ 10.11646/zootaxa.5222.2.4
publication LSID	lsid:zoobank.org:pub:55F69A43-2837-4E5F-936D-5ADD23BA5790
DOI	https://doi.org/10.5281/zenodo.7468432
persistent identifier	https://treatment.plazi.org/id/03AB87FF-6B12-175A-819B-F9D9FD38F8D8
treatment provided by	Plazi
scientific name	Sejanus epicurus
status	sp. nov.

Treatment

Sejanus epicurus n. sp.

( Figs. 1A–J View FIGURE 1 ; 2I–J View FIGURE 2 ; 4A–D View FIGURE 4 ; 5A–G View FIGURE 5 ; 6A–F View FIGURE 6 ; 7A–D View FIGURE 7 )

Material examined. Holotype (♁). TAIWAN: Pingtung Co., Manchu [Boánchiu], branch of Chunggang stream, near north border of Mt. Nanren , 22°06'17.0"N 120°51'24.3"E, 60 m alt., Hibiscus taiwanensis , 20 Mar 2017, T. Yasunaga et al. ( NMNS) ( AMNH _ PBI 00380760 View Materials ) GoogleMaps . Paratypes: TAIWAN: Same data as for holotype, 43♁ 43♀ ( AMNH, CNC, TYCN) GoogleMaps ; Pingtung Co., Mudan Township, Shimen Village, Cacevakan (historic ruin), 22°06'34.9"N 120°48'06.1"E, 200 m alt., Hibiscus taiwanensis , 16 Mar 2017, T. Yasunaga et al., 19♁ 17♀ ( CNC, NMNS, TYCN) GoogleMaps ; Pingtung Co., Manchu, Lite Village, Xilaikou stream, 22°00'48.5"N 120°52'39.2"E, 20 m alt., Hibiscus taiwanensis , 21 Mar 2017, T. Yasunaga ( TYCN) GoogleMaps .

Diagnosis. Readily recognized by its small size; relatively fragile surface structure; creamy yellow antenna, with darkened apical 1/4 of segment II; shiny black hemelytra with white base of cuneus ( Fig. 1H–J View FIGURE 1 ); and almost totally creamy yellow legs ( Fig. 2I–J View FIGURE 2 ). Any other known congeners with fuscous dorsum have more or less darkened femora.

The immature forms are uniquely pale green with only apex of the antennal segment II reddish brown ( Fig. 1E–G View FIGURE 1 ), whereas the nymphs of most Japanese species have reddish brown basic coloration (e.g. Fig. 3B, G–H View FIGURE 3 ), as documented by Yasunaga (2001b), Yasunaga et al. (2013) and Yasunaga & Duwal (2021).

Description. Male: Macropterous. Body elongate oval, subparallel-sided, small-sized (2.0– 2.2 mm in total length), with relatively fragile integument; dorsal surface shiny fuscous, polished, with uniformly distributed, pale brown, simple, semierect setae. Head somewhat oblique; eye small; vertex weakly carinate basally. Antenna creamy yellow, relatively short; segment I about as thick as II; apical 1/4 of segment II dark reddish brown; apical parts of segments III and IV slightly darker. Labium shiny creamy yellow, reaching apex of metacoxa; apical part of segment IV reddish brown. Pronotum polished, minutely punctate; mesoscutum elevated anteriorly; scutellum flat; pleura dark brown, with sparsely distributed, simple, reclining setae ( Fig. 5B View FIGURE 5 ); metathoracic scent efferent system grayish brown, with narrow orifice and small, semi-circular peritreme ( Fig. 5C View FIGURE 5 ). Hemelytron polished, fuscous; basal margin of cuneus with white crescent fascia that is usually not interrupted; membrane including veins dark smoky brown. Coxae and legs creamy yellow; base and apex of each tibia suffused with orange ( Fig. 2I–J View FIGURE 2 ): apex of each tarsomere III reddish; meta-tarsomere II longer than III ( Fig. 5F View FIGURE 5 ); pretarsal structure as in Fig. 5G View FIGURE 5 ; parempodia setiform, short; pulvilli rather widened. Abdomen shiny dark brown, sometimes whitish anteriorly. Male genitalia ( Figs. 4A–B View FIGURE 4 ; 6A–F View FIGURE 6 ): Phallotheca slender, tapered and weakly curved ( Fig. 6A, D View FIGURE 6 ); left paramere with short, narrow hypophysis ( Fig. 6B View FIGURE 6 ); right paramere with small, blunt-tipped hypophysis ( Fig. 6C View FIGURE 6 ); endosoma (vesica) C-shaped ( Fig. 6E View FIGURE 6 ), with short, minutely spinulate apex ( Fig. 6F View FIGURE 6 ).

Female: Not sexually dimorphic, but body slightly wider and ovoid ( Figs. 1H View FIGURE 1 ). Antennal segment II somewhat shorter. Female genitalia (4C–D; 7A–D): Generally simple in form; sclerotized ring thin-rimmed, rather oval ( Figs. 4C View FIGURE 4 , 7A View FIGURE 7 ); interramal sclerite with rather sparsely distributed comb-like microstructures ( Fig. 7C View FIGURE 7 ).

Measurements: See Table 1 View TABLE 1 .

Etymology. Named for an ancient Greek philosopher Epicurus, (or Epikouros, 341–270 BC); one of his philosophies suggested ‘live secretly’, which is somewhat reminiscent of the cryptic lifestyle of this new species.

Biology. Both adults and every stage of immature forms of this unique new species were observed to inhabit abaxial leaves ( Fig. 1C View FIGURE 1 ) and insides of bracts ( Fig. 1A, E View FIGURE 1 ) of Hibiscus taiwanensis . On the same plant, an undetermined thrips, and predaceous Termatophylum orientale Poppius, 1915 (Deraeocorinae: Termatophylini) ( Fig. 1K View FIGURE 1 ) and Bilia sp. ( Anthocoridae : Oriini ) were found to coexist.