Eurygaster dilaticollis Dohrn, 1860

Neimorovets, Vladimir, 2020, Review of the genus Eurygaster (Hemiptera: Heteroptera: Scutelleridae) of Russia, Zootaxa 4722 (6), pp. 501-539 : 514-516

Eurygaster dilaticollis Dohrn, 1860

Figs 14 , 21 , 27 , 33 , 39 , 51 , 62 and 63 .

Eurygaster dilaticollis Dohrn, 1860:100 .

Material examined. RUSSIA: Crimea Rep .: 1♂, Khir – Alan Range , 31.v.1954, Unknown collector . 1♂, Valley of the Kosa River , 31.v.1954, Unknown collector . 1 nymph 5 th instar, Crimean Nature Reserve , 15.viii.1954, Loginova leg. Krasnodar Ter.: 2♂, [ Kuban Prov. ], 21.v.1911, D. Volnukhin leg. Stavropol Ter.: 1♂, Stavropol , v.1921, V. Lutchnik leg. Dagestan Rep.: 1♂, 1♀, Gunib , 12.vii.1924, 25.vii.1924, Ryabov leg. Volgograd Prov.: 2♂, 4♀, Sarepta [now part of Krasnoarmeysk District of Volgograd], Becker leg. 2♂, 2♀, Sarepta, Unknown date, Jakovlev leg. 1♀, Sarepta, Unknown date, A. Kushakevitch leg. 1♂, 1♀, Saltov Forest [now Specially Protected Natural Territory], 25–30.vi.1936, Vorontsov leg. Kirov Prov.: 1♂, Yaransk , 15.viii.1899, Poretsky leg. Bashkortostan Rep.: 2♂, 2♀, Bashart Mount , 6.vii.1948, Nasirova leg. 2♂, Alkino, 12 Jull 1899, Poretsky leg. 4♂, 4♀, Belebey , 21, 24.vi.1907, 13.vii.1907, 14–16.vii.1908, A. Grigoriev leg. 1♂, 6 nymph 5 th instar, Alsheyevsky District, Aksenovo , 1–2.vii.1908, 14–16.vii.1908, A. Grigoriev leg. 1♂, the Irgizla River , 6, 7.vii.1899, Jacobs & Schmidt leg.

Chelyabinsk Prov.: 1♀, Agapovsky District , 1–6.vi.1928, Unknown collector . Altai Ter.: 1♂, Pavlovsk , 30.v.1943, Unknown collector . 1♀, Slavgorod , 12.vii.1922, A. Reichard & V. Satalkin leg. 2♂, Zmeinogorsk , 8.viii.1930, Un- known collector . Kemerovo Prov.: 1♂, 2♀, Bachatsky [former Bachati], 10, 19–26.vi.1908, Unknown collector . Krasnoyarsk Ter.: 1♂, Taseyevo , 14.vii.1914, Varaksina leg. 1♀, Ribnoe [former Ribinskoye], 29.vi.1912, Velim- chik leg . 1♀, Krsnoyarck, Afontova Gora , 12.viii.1901, Pokrovsky leg. 2♂, 3♀, Minusinsky District , 9.ix.1930, Lukyanovic leg. Tyva Rep.: 8 nymphs 5 th instar, Sosnovka, Eastern Tannu–Ola Mountains , 2–3.vii.1948, 2.vii.1949, Dyatlova leg. Irkutsk Prov.: 1♂, Kuitun , 28.vii.1934, Rubtsov leg. 1♂, Balagan steppes, Molka , 1.vii.1932, Za- hvatkin leg . 1♀, near Ikrutsk , 1.vii.1912, Silantiev leg. 1♀, Oek, Irkutsk, 28.vii.1912, Sergeeva leg. 1♀, [Irkutsk Governorate], 31.vii.1926, Pokrovsky leg. 29♂, 28♀, Irkutsk, Jakovlev leg.

Additional material examined. KAZAKHSTAN: West Kazakhstan Prov.: Yanvartsevo, right shore of Ural River , 9.ix.1949, 1♀ , 11.ix.1949 1♂, Kiritshenko leg.

Diagnosis. Body length 8.5–11.0 mm. Body less convex than in other species of the genus. Puncturation of body usually shallow ( Figs. 62, 63 ). Mandibular plates same length with clypeus and not convergent in front of clypeus. Lateral margins of mandibular plates distinctly convex ( Fig. 21 ). Buccula at middle almost as high as width of second segment of labium. Eye 3.1–4.0 times as high as buccula at middle ( Fig. 27 ). Pronotum usually 2.4–2.5 times as wide as long. Anterolateral margins of pronotum convex, humeral angles widely rounded and not extending beyond margin of corium. Smooth, sparsely punctured ridge along median line of scutellum more or less clearly visible. Callouses next to base of scutellum indistinct. Aedeagus with four pairs of conjunctival appendages ( Figs. 33 , 39 A–C); one pair very small and located at base of first pair of big appendages. Blade of crown of paramere ½ as long as stem (dorsal view). Width of base of crown equal to width of middle of stem (dorsal view) ( Fig. 39 D–39F). Laterotergite IX at most twice as wide as long and 1.2 as long as valvifer VIII. Laterotergite IX not reaching lateral excisions of abdominal sternite VII ( Fig. 51 ).

Eurygaster dilaticollis differs from E. austriaca , E. integriceps , E. maura , and E. testudinaria primarily in wider pronotum. Pronotum in all these species is usualy 2.1–2.3 times as wide as long. Unlike E. laeviuscula and E. austriaca , the mandibular plates of E. dilaticollis are not longer than the clypeus and never converge in front of the clypeus. Aedeagus of E. integriceps and E. testudinaria with two pairs of conjunctival appendages, and aedeagus of E. maura with one pair of conjunctival appendages.

Notes. The small conjunctival appendages of the aedeagus are hardly visible; that is the reason why some authors mentioned only three pairs of conjunctival appendages ( Putchkov 1961, Kerzhner & Jaczewski 1964, Vinokurov & Kanyukova 1995).

Natural History and Bionomics. A xerophilous species associated with undisturbed steppes, it rarely occurs in humid areas with meadow vegetation. It was reported to fed on a number of cereals including Festuca taurica (Hack.) A. Kern. ex Trautv. , Phleum phleoides (L.) H. Karst., Bromus riparia (Rehmann) Holub , Briza spicata (M. Bieb.) Chrtek & Hadac. In Crimea, E. dilaticollis was found at altitudes of 900–1000 m. The new generation of imago may be found starting from the second half of June but IV–V instar nymphs can be caught in mid-July. In Crimea for some years the I–III instar nymphs were recorded at the end of July, and the adults of the new generation appeared not earlier than in August ( Putchkov 1961). In Bashkortostan Republic, the hibernating specimens were found in the forest litter under the trees and in the thickets of perennial grasses. There is one generation per year ( Putchkov 1961, 1972).

Distribution. In Europe, the northern border of distribution passes through the southern France, Italy, Slovenia, Hungary, and Ukraine; the species also occurs in all Transcaucasian countries, Turkey, northwestern Kazakhstan, and Kyrgyzstan ( Putchkov 1961, Vinokurov & Kanyukova 1995, Göllner-Scheiding 2006, Babichev & Vinokurov 2011, Syromyatnikov et al. 2017). In Russia, the species is distributed in the steppe areas of the European Russia and southern Siberia. The northern border of distribution passes through the Kursk, Lipetsk, Tambov, and Ulyanovsk Provinces, Republic of Bashkortostan south of Ufa, Chelyabinsk Province south of Chelyabinsk, Tyumen Province, Kemerovo Province (Bachatsky), south of Krasnoyarsk Territory (Taseyevo), and Irkutsk Province south of Kuitun.

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 38–41. 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). view from abow. 38—E. austriaca (Schrank, 1776); 39—E. dilaticollis Dohrn, 1860; 40, 41—E. integriceps Puton, 1881.

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.