Ommatidiotus nigritus Matsumura 1911
Creators: name: Park, Jaekook
name: Jung, Sunghoon
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hemiptera
Caliscelidae
Ommatidiotus
Ommatidiotus nigritus

description: Ommatidiotus nigritus Matsumura, 1911
(Figs 8A–B, 9A–E, 10A–E, 11A–F)
Ommatidiotus nigritus Matsumura, 1911: 32; Metcalf, 1958: 104.
Diagnostic characters. Recognized by body generally black. Coryphe almost as long as the distance between the eyes, rounded in front, with a longitudinal furrow in the middle, which is gradually widened towards the tip. Metope a little hollowed in the middle. Pronotum without median keel. Mesonotum with 3 keels. Forewing unicolorous pitch brown, median keel low. Abdomen and legs unicolorous black. Female length 4.5 mm (Figs 9A–E) (Matsumura, 1911). In males, venter and metope more or less black, forewings blackened from costal margin in the shape of a stripe to radial, medial and even claval veins; middle part light brown, with ochraceous longitudinal stripes between main veins. 3.5–5 mm (Figs 10A–E) (Anufriev & Emeljanov, 1988).
Redescription. Male. COLORATION: General coloration of body light brown. Ventral parts of body fuscous, contrast with background distinctly. Coryphe concolorous with background with longitudinal reddish stripes, contrasted bicolored, surpassing pronotum and almost reaching posterior margins of mesonotum. Compound eyes darker than background. Pronotum with reddish median stripe. Paranotal lobes fuscous. Forewings with narrow reddish stripe medially, with strong fuscous markings on margins of costal area reaching posterior margins, yellowish stripes weakly developed between cubital and median cells, not reaching posterior margins. Femur black. Tibiae and tarsus light brown (Figs 10A–E). SURFACE AND VESTITURE: Head, body and forewings with sparse setae. STRUCTURE: Head. Coryphe blunt, length slightly shorter than width at midline; anterior margin round but slightly angulated, posterior margin weakly concave (Fig. 10C). Metope short and blunt, lateral keels converging narrower to apical, sublateral carinae visible (Fig. 10E). Thorax. Pronotum distinctly shorter than coryphe at midline, with median carina reaching anterior and posterior margin. Paradiscal fields of pronotum narrower behind eyes. Paranotal lobes of pronotum ovate, protruding ventrally. Posterior margin of pronotum concave. Mesonotum large, almost three times longer than pronotum, anterior margin convex, with lateral carinae reaching posterior margin (Figs 10C–D). Forewings elongated, surpassing posterior margin of abdomen and not converging at apex (Figs 10A–B). Abdomen. In lateral view, almost flat; length of each tergites almost similar (Fig. 10B). Genitalia. Genital block in lateral view slightly wide basally, apical to posterior margins irregularly concaved (Fig. 11B). Aedeagus long and asymmetrical, complex endosome ovovate ventroapically (Fig. 11C). In dorsocaudal view, apical of complex shaped irregular star-like, upper three processes relatively short, protruding upward, lower two processes protruding ventrally and left process curved to upward (Fig. 11D). In lateral view, a pair of ventral aedeagal hooks asymmetrical, left hook parallel with complex and slightly curved, right hook vertical with complex and slightly curved, widest at middle; a pair of subapical processes strongly developed at middle, not reaching posterior margins and branched at apical (Fig. 11C); genital style roundly widest at basal, pointed at apical and strongly curved; capitulum of style spinous (Fig. 11E); Anal tube in dorsal view, ovate and convex apically; anal column placed at middle and small, not reaching the posterior margin (Fig. 11F). Female. COLORATION: General coloration of body black. Forewings slightly bright than background, fuscous. Abdomens and abdominal sternites concolorous. Femur black. Tibiae and tarsus concolorous with background (Figs 9A–E). SURFACE AND VESTITURE: Head, body and forewings with sparse setae, rough. STRUCTURE: Head. Coryphe blunt, length as wide as width at midline; anterior margin round, posterior margin weakly concave (Figs 9C–D). Metope short and blunt in lateral view, lateral keels converging narrower to apical, sublateral carinae visible (Fig. 9E). Thorax. Pronotum distinctly shorter than coryphe at midline. Paradiscal fields of pronotum narrower behind eyes. Paranotal lobes of pronotum ovate, protruding ventrally. Posterior margin of pronotum concave. Mesonotum large, almost three times longer than pronotum, anterior margin convex, with lateral carinae reaching posterior margin (Figs 9C–D). Forewings elongated, surpassing posterior margin of abdomen and not converging at apex (Figs 9A–B). Abdomen. in lateral view, almost flat; length of each tergites almost similar (Figs 9B). See Matsumura (1911) for original description also.
Measurements (in mm). Male (n=1) / Female (n=1). Body length (including forewing): 3.51/4.58; body length (excluding forewing): 3.05/4.10; body width (including forewing): 1.29/1.57; head length: 0.74/0.94; head width (including eyes): 1.08/1.30; coryphe length: 0.45/0.59; coryphe width: 0.57/0.71; metope length: 0.70/0.94; metope width: 0.64/0.79; pronotum length: 0.34/0.40; pronotum width: 0.75/0.83; mesonotum length: 0.59/0.70; mesonotum width: 0.81/1.03; forewing length: 2.57/3.44.
Material examined. Lectotype: 1♀, Sakhalin; 30.IX.1905, Yoichiro Ikuma leg. (SEHU); 1♂, Sakhalin; collecting date and collector unavailable with no labels. (SEHU).
Distributions. Russia (Sakhalin) (Matsumura, 1911, 1916).
Hosts. Unknown.
Ecology. Sedge marshes and swamp meadows. Late July to early September (Anufriev & Emeljanov, 1988).
Remarks. According to Liang & Suwa (1998), ‘This species was described from four female specimens. We have found only one female syntype’. The depository contained a female lectotype, which is consistent with the previous study.
We examined a male specimen that corresponds to Anufriev & Emeljanov (1988) from the Matsumura collections, but the female lectotype and the protologue (Matsumura, 1911) differed from the male specimen and the morphological characters in Anufriev & Emeljanov (1988) (See the respective redescriptions of the male and female habitus above).
Further verification is necessary to confirm that examined specimens are the same species since there are no specimens of the same gender available for comparison.
description: Published as part of Park, Jaekook & Jung, Sunghoon, 2024, The genus Ommatidiotus Spinola (Hemiptera: Auchenorrhyncha: Caliscelidae) from the Korean Peninsula and neighboring countries, pp. 172-190 in Zootaxa 5496 (2) on pages 183-187, DOI: 10.11646/zootaxa.5496.2.2, http://zenodo.org/record/13346536