Isometopus japonicus Hasegawa, 1946

Kim, Junggon & Jung, Sunghoon, 2016, Taxonomic review of the genus Isometopus (Hemiptera: Miridae: Isometopinae) from the Korean Peninsula, with description of a new species, Zootaxa 4137 (1), pp. 137-145 : 140-144

publication ID	https://doi.org/ 10.11646/zootaxa.4137.1.11
publication LSID	lsid:zoobank.org:pub:AAFBAA59-9193-41CE-AEAF-D85138793B84
DOI	https://doi.org/10.5281/zenodo.6085575
persistent identifier	https://treatment.plazi.org/id/A71D8791-FF9B-8D40-FF39-FF7546D89172
treatment provided by	Plazi
scientific name	Isometopus japonicus Hasegawa, 1946
status

Treatment

Isometopus japonicus Hasegawa, 1946 View in CoL

( Figs. 1 View FIGURE 1 B–D, 1F–J, 2A–D, 3A–C, 4B, 6B–D)

Isometopus japonicus Hasegawa, 1946: 1 View in CoL ; Miyamoto, 1957: 77; Miyamoto, 1961: 222.

Diagnosis. Recognized by the dark brown head, pronotum and scutellum ( Figs. 1 View FIGURE 1 B–C); the pale markings on the posterior margin of the head ( Figs. 1 View FIGURE 1 H–I); the apical part of second antennal segment dark brown in males, pale brown in females; face with sparse punctures on the frons and with indistinctly transverse wrinkles ( Figs. 1 View FIGURE 1 F–G); hemelytron mostly all sub-hyaline and apical margin of cuneus dark brown in males ( Fig. 1 View FIGURE 1 B); hemelytron almost all dark brown in females ( Fig. 1 View FIGURE 1 C); endosoma membranous with tiny spinules at apex in males ( Figs. 2 View FIGURE 2 D, 3C); apex of sclerotized ring sharply projected and strongly curved medially in females ( Fig. 4 View FIGURE 4 B).

Redescription. Male: Body oval, length 2.82–2.91. COLORATION: dark brown and hyaline. Head: generally dark brown, posterior margin of head pale brown; ocellus reddish brown; antennae generally brown except for dark apical part of second antennal segment; tylus dark brown; rostrum generally brown, first rostral segment reddish brown, apical part of third rostral segment and basal part of fourth rostral segment pale brown. Thorax: pronotum and scutellum entirely dark brown; hemelytra mostly sub-hyaline; clavus generally brown, anterior part of clavus darker than posterior part; margin of corium brown; margin of embolium brown; cuneus mostly sub-hyaline, posterior margin of cuneus brown; membrane grayish; legs generally brown; femur mostly dark brown except for yellowish brown apical part; tibia pale brown except for dark apex; tarsus brown. Abdomen: dark brown. SURFACE AND VESTITURE: covered with densely golden pubescence; pronotum, scutellum and hemelytra with distinct punctures. STRUCTURE: Head: flattened anteriorly with sparse punctures and with indistinctly transverse wrinkles, width upper half including compound eyes slightly wider than lower part including lorum ( Fig. 1 View FIGURE 1 F), ocelli present on vertex; vertex width approximately as wide as width of one compound eye, vertex width as wide as length third antennal segment; antennae originated at ventral margin of head; antennae cylindrical in form; proportion of first to fourth antennal segments 0.1:0.6:0.2:0.1; rostrum reaching to second abdominal segment; proportion of first to fourth rostral segments 0.3:0.3:0.3:0.4. Thorax: pronotum trapezoid, posterior margin of pronotum with two concave lines; mesoscutum broad; scutellum equilateral with two concave lines; lateral margin of hemelytra curved; cuneal fracture developed; membrane with one cell; legs generally slender; femur thick; tibia slender; tarsus with two segments. Abdomen: rounded, almost reaching to apex of cuneus. GENITALIA: genital segment rounded with asymmetric parameres ( Figs. 2 View FIGURE 2 A–D, 3A–C); left paramere scythe-shaped with somewhat large hypophysis and sensory lobe ( Figs. 2 View FIGURE 2 B, 3A), right paramere curved with sharp hypophysis ( Figs. 2 View FIGURE 2 C, 3B); endosoma membranous with small spinules at its apex, seminal duct coiled in phallotheca ( Figs. 2 View FIGURE 2 D, 3C).

Female: Body oval, length 2.57–3.06. COLORATION: dark brown. Head: generally dark brown, posterior margin of head distinct pale brown; compound eyes dark brown and reddish brown; ocellus reddish brown; antennae generally brown except for pale apical part of second antennal segment; tylus dark brown; rostrum generally brown, first rostral segment reddish brown, apical part of third rostral segment and basal part of fourth rostral segment pale brown. Thorax: pronotum and scutellum entirely dark brown; hemelytra mostly dark brown; base of corium and embolium pale brown; membrane grayish and darker than male; legs generally brown, femur mostly dark brown except for yellowish brown apical part, tibia pale brown except for dark apex, hind tibia darker than other tibia, tarsus brown. Abdomen: dark brown. SURFACE AND VESTITURE: covered with densely golden pubescence; pronotum, scutellum and hemelytra with distinct punctures. STRUCTURE: Head: flattened anteriorly with sparse punctures and with indistinctly transverse wrinkles, upper part width including compound eyes slightly narrower than lower part including lorum ( Fig. 1 View FIGURE 1 G); ocelli present on vertex; vertex width approximately as wide as one compound eye, vertex width 0.5 times as wide as length of third antennal segment; antennae originated at ventral margin of head; antennae cylindrical form; proportion of first to fourth antennal segments 0.1:0.6:0.4:0.2; rostrum reaching to ovipositor of abdomen; proportion of first to fourth rostral segments 0.3:0.3:0.3:0.4. Thorax: pronotum trapezoidal, posterior margin of pronotum with two concave lines; mesoscutum broad; scutellum equilateral with two medial concave lines; lateral margin of hemelytra curved; cuneal fracture developed; membrane with one cell; legs generally slender; femur thick; tibia slender; tarsus with two segments. Abdomen: rounded, almost reaching to apex of membrane. GENITALIA: genital chamber somewhat simple, bursa copulatrix with distinct a pair of sclerotized rings; apex of sclerotized ring sharply projected and strongly curved medially ( Fig. 4 View FIGURE 4 B).

Description of nymph. Last instar: Body almost circular, length (from tylus to apex of abdomen) 2.47–2.62. COLORATION: grayish pale brown ( Fig. 6 View FIGURE 6 D). Head: pale brown with a pair of dark spot around compound eye; vertex mottled pale brown; first and second antennal segment pale brown, third and fourth antennal segment dark brown; rostrum mostly dark brown. Thorax: pronotum grayish brown, middle part darker than each pronotal angle; scutellum grayish brown; wing pad grayish dark brown; hind wing pad with a pair of dark spots medially; legs generally grayish dark brown; tibia grayish brown except for pale apex; tarsus brown. Abdomen: generally paler grayish brown than scutellum, with tiny dark spots, outer margin of each abdominal segment dark brown; middle part of first and second abdominal segment dark. SURFACE AND VESTITURE: body granular, matt; tibia with dense spines. STRUCTURE: Head: semicircular dorsally, posterior margin straight; frons concave; tylus flat; ocelli absent; vertex width approximately as wide as one compound eye width, vertex width narrower than third antennal segment; antennae cylindrical form; rostrum reaching to second abdominal segment. Thorax: pronotum semicircular, posterior margin of pronotum slightly winding form; wing pad developed, extending to third abdominal segment; legs generally slender; femur thick; tibia slender; tarsus with two segments. Abdomen: rounded.

Measurements. Male (n=2)/Female (n=2) Body length, tylus–apex of membrane: 2.82–2.91/2.57–3.06; head length, excluding collar: 0.16–0.17/0.18–0.20; head width, including compound eyes: 0.69–0.70/0.75–0.79; vertex width: 0.20–0.21/0.23–0.27; interocular width: 0.06–0.07/0.12–0.14; 1st antennal segment length: 0.09–0.10/0.13– 0.14; 2nd antennal segment length: 0.60–0.62/0.57–0.60; 3rd antennal segment length: 0.24–0.25/0.46–0.48; 4th antennal segment length: 0.13–0.14/0.19–0.21; total antennal length: 1.06–1.11/1.35–1.43; 1st rostral segment length: 0.29–0.30/0.31–0.33; 2nd rostral segment length: 0.34–0.39/0.35–0.37; 3rd rostral segment length: 0.27– 0.31/0.33–0.34; 4th rostral segment length: 0.40–0.41/0.43–0.46; total rostral length: 1.30–1.41/1.42–1.50; mesal pronotal length: 0.40–0.41/0.36–0.41; basal pronotal maximal width (straight): 1.22–1.23/1.17–1.21; anterior scutellum width: 0.96–0.98/0.94–0.98; mesal scutellum length: 0.92–0.97/1.01–1.06; outer embolial margin length (straight): 1.17–1.19/1.21–1.24; outer cuneal margin length (straight): 0.50–0.52/0.45–0.48; maximal width across hemelytron: 0.78–0.79/0.79–0.85; foreleg (femur: tibia: tarsus): 0.53–0.58:0.64–0.67:0.25–0.29/0.58–0.61:0.64– 0.68:0.30–0.32; mid leg (femur: tibia: tarsus): 0.62–0.63:0.74–0.78:0.31–0.33/0.63–0.66:0.75–0.79:0.32–0.35; hind leg (femur: tibia: tarsus): 0.72–0.79:1.06–1.07:0.33–0.35/0.76–0.79:0.95–0.99:0.32–0.35.

Materials examined. [ CNU] 7♂♂5♀♀, Hyoja-dong, Wansan-gu, Jeonju-si, Jeollabuk-do, Korea, 10.v.2015, on Zelkova serrata, J.G. Kim ; [ CNU] 2♂♂2♀♀, Tottori Pref., Honshu, Japan, 23.vi.2015, on Zelkova serrata, J.G. Kim.

Hosts. Zelkova serrata (Thunb.) Makino (Ulmaceae) * ( Fig. 5 View FIGURE 5 B). Distributions. Korea *, Japan.

Discussion. Young nymphs (especially 2nd instar and 3rd instar) of this species are mostly found around mosses on bark of Zelkova serrata ( Fig. 6 View FIGURE 6 C).