Eurygaster laeviuscula Jakovlev, 1886

Neimorovets, Vladimir, 2020, Review of the genus Eurygaster (Hemiptera: Heteroptera: Scutelleridae) of Russia, Zootaxa 4722 (6), pp. 501-539 : 521-522

Eurygaster laeviuscula Jakovlev, 1886

Figs. 16 , 23 , 29 , 35 , 42 , 53 , 64, 65 .

Eurygaster laeviuscula Jakovlev, 1886: 78 , 80 (as laevluscnla on p. 78).

Eurygaster laeviuscula Jakovlev, 1903: 319 .

Type material examined. HOLOTYPE Eurygaster laeviuscula Jakovlev, 1886 : RUSSIA: Irkutsk Prov.: Kultuk , 1♂, Jakovlev leg.

Material examined. Amur Prov.: 1♂, 1♀, Mouth of Bureya River [former Post IV], 6.vi.1904, Malinovsky leg. Primorsky Ter .: 1♂, Vinogradovka , 19.vii.1929, Kiritshenko leg. 1♀, Riva Komarovka [former Suputinka] tributary of Razdolnaya Riva [former Suifun], 8.vii.1937, Richter leg. 1♀, Troitskoe, Lake Khanka , 27–28.vi.1908, A.I. Chersky leg. 1♀, Pogranichny [former Grodekovo Railway Station], 20.viii.1912, A.I. Chersky leg. 1♂, Ka- men–Rybolov, Lake Khanka , 5.vii.1908, A.I. Chersky leg. Kamen–Rybolov , 1♂, Lake Khanka , 10.vii.1910, A. Tarabarov leg. 1♀, Ussurisky Nature Reserve [former Suputinsky Nature Reserve], 4.x.1968, B. Mamaev leg.

Additional material examined. MONGOLIA: Töv Prov.: 1♀, Noin–Ula ( Suzukte ), SE Kentey, SW Ulaan- baatar [former Urga], 1–24.v.1924, Kozlov leg.

Diagnosis. Body length 8–10 mm. Mandibular plates longer than clypeus and contiguous or almost contiguous in front of the clypeus. Lateral margins of mandibular plates slightly convex ( Fig. 23 ). Buccula at middle almost as high as width of second segment of labium. Eye 3.3–4.6 times as high as buccula at middle ( Fig. 29 ). Pronotum 2.3– 2.7 times as wide as long ( Figs. 64, 65 ). Anterolateral margins of pronotum slightly or distinctly convex. Humeral angles of pronotum not extending or very slightly extending beyond margin of corium. Whitish ridge along median line of scutellum usually clearly visible. Aedeagus with one pair of very large distal conjunctival appendages and one pair of shorter basal appendages; two pairs of small spines at base of each distal conjunctival appendage not clearly visible ( Figs. 35 , 42 A–42C). Stem of paramere 4.0 times as long as blade of crown in dorsal view; blade of crown bends steeply laterally ( Figs. 42 D–F). Laterotergite IX strongly conical, twice as wide as long, 0.8–1.0 times as long as valvifer VIII ( Fig. 53 ).

Eurygaster laeviuscula differs from E. dilaticollis , E. integriceps , E. maura , and E. testudinaria by the mandibular plates, which are longer than clypeus and contiguous or almost contiguous in front of it. Eurygaster laeviuscula differs from E. austriaca by the size and proportions of the body. The lateral margins of mandibular plates of E. austriaca are almost straight and the head is almost triangular (seen from above, Figs. 19, 20 ); the lateral margins of mandibular plates of E. laeviuscula are slightly convex and the head is clearly rounded (seen from above, Fig. 23 ).

Natural History and Bionomics. Almost nothing is known about this species. It was noted that it lives in meadow cereals ( Poaceae ) near water bodies ( Kulik 1965, Putchkov 1972, Kuzhuget & Vinokurov 2016). E. laeviuscula appears to have one generation per year and the imago is the hibernating stage.

Distribution. In Russia: Tyva Republic, Irkutsk Province, Khabarovsk (south) and Primorsky Territories. Oth- er countries: Mongolia (near Ulaanbaatar), Northern China, Korea ( Josifov & Kerzhner 1978, Nonnaizab 1986, Vinokurov et al. 1988, Vinokurov & Kanyukova 1995, Göllner-Scheiding 2006, Vinokurov et al. 2010, Kuzhuget & Vinokurov 2016).

Figures

FIGURES 13–18. Head of Eurygaster, anterior view. 13—E. austriaca (Schrank, 1776), male; 14—E. dilaticollis Dohrn, 1860, female; 15—E. integriceps Puton, 1881, male; 16—E. laeviuscula Jakovlev, 1886, male; 17—E. maura (Linnaeus, 1758), male; 18—E. testudinaria (Geoffroy, 1785), female.

FIGURES 19–25. Head of Eurygaster, view from above. 19—E. austriaca (Schrank, 1776), male (apices of mandibular plates converge); 20—E. austriaca (Schrank, 1776), male (apices of mandibular plates don’t converge); 21—E. dilaticollis Dohrn, 1860, female; 22—E. integriceps Puton, 1881, male; 23—E. laeviuscula Jakovlev, 1886, male; 24—E. maura (Linnaeus, 1758), male; 25—E. testudinaria (Geoffroy, 1785), female.

FIGURES 26–31. Head of Eurygaster, left lateral view (A—photo; B—scheme). 26—E. austriaca (Schrank, 1776), female; 27—E. dilaticollis Dohrn, 1860, male; 28—E. integriceps Puton, 1881, male; 29—E. laeviuscula Jakovlev, 1886, female; 30—E. maura (Linnaeus, 1758), male; 31—E. testudinaria (Geoffroy, 1785), male.

FIGURES 32–37. Schemes of aedeagus of Eurygaster (A—dorsal view, B—dorsolateral view, C—left lateral view). 32—E. austriaca (Schrank, 1776); 33—E. dilaticollis Dohrn, 1860; 34—E. integriceps Puton, 1881; 35—E. laeviuscula Jakovlev, 1886; 36—E. maura (Linnaeus, 1758); 37—E. testudinaria (Geoffroy, 1785).

FIGURES 42–45. Male genitalia of Eurygaster (aedeagus: A—dorsal view, B—dorsolateral view, C—left lateral view; parameres: D—right paramere, E—left paramere, F—left paramere, dorsal view). 42—E. laeviuscula Jakovlev, 1886 (holotype); 43—E. maura (Linnaeus, 1758); 44, 45—E. testudinaria (Geoffroy, 1785).

FIGURES 50–55. Female’s postgenital segments of Eurygaster. 50—E. austriaca (Schrank, 1776); 51—E. dilaticollis Dohrn, 1860; 52—E. integriceps Puton, 1881; 53—E. laeviuscula Jakovlev, 1886; 54—E. maura (Linnaeus, 1758); 55—E. testudinaria (Geoffroy, 1785).

FIGURES 56–65. Species of Eurygaster. 55–65—E. austriaca (Schrank, 1776), the different variants of coloration: 56, 57 and 59—female, Russia, Voronezh Province: 60, 61—female, Russia, Belgorod Province. 62–63—E. dilaticollis Dohrn, 1860: 62—male, 63—female. 64–65—E. laeviuscula Jakovlev, 1886: 64—female, 65—male.