Stigmus eurasiaticus Mokrousov, 2017

Mokrousov, Mikhail, 2017, To the knowledge of digger wasps of subfamily Pemphredoninae (Hymenoptera: Crabronidae) of Russia, Far Eastern Entomologist 337 (337), pp. 1-16 : 9-13

Stigmus eurasiaticus Mokrousov , sp. n.

Figs 6–12 , 16–17 , 20–23

Stigmus convergens: Budrys, 1987: 52 (part, Khabarovsk Terr., Primorskiy Terr.), 1995: 404

(part, Irkutsk Prov., Khabarovsk Terr., Primorskiy Terr.); Mokrousov, 2010: 63 (Nizhny Novgorod Prov., Mari El Rep., Chuvash Rep.); Mokrousov et al., 2011: 80 (Chuvash Rep.).

TYPE MATERIAL. Holotype: ♀, Russia: Chuvash Rep., Cheboksary , 56°07'44''

N 47°08'48''E, 6.VI 2010 (L. Egorov) [ ZISP]. Paratypes: Russia: Karelia, Petrozavodsk , 1.IX 2015 (A. Humala), 1♀ [ ZISP]; Nizhny Novgorod, 25.VI 2004 (Yu.

Katyshev, M.), 1♀ [ MC]; 19.VIII 2009 (M.) , 2♀ [ MC]; Cheboksary, 56°07'44''N

47°08'48''E, 28.VI 2010 (L. Egorov), 1♀ [ MC]; Mari El Rep., near Nezhnur vill .,

56°51.98'N 46°26.89'E, 29.VIII 2009 (M.), 1♀ [ MC]; Il’inka vill ., 56°47.695'N

47°57.349'E, 1.IX 2009 (M.), 1♀ [ ZISP]; Yekaterinburg, 29.VII 2000 (A. Ivanov) ,

1♀ [ ZISP]; Chelyabinsk Prov., Ozersk city, vill. Metlino , 18.VIII 2006 ( R.) , 1♀

[ ZISP]; Altai Rep.: 20 km SE Ongudai , 17.VII 2007 (B.), 1♂ [ ZISP]; Tchemal, 19 –

22.VII 2007 (B.), 1♂ [ ZISP]; Artybash , near Teletzkoe lake, 24–27.VII 2007 (B.),

1♀ [ ZISP]; near Khabarovsk, Khehtzir , 23.VII 1981 (D. Kasparyan) , 1♀ [ ZISP] ;

same, 3.VII 1983 (D. Kasparyan), 1♂ [ ZISP]; Primorskiy Terr.: Nature Reserve

" Ussuriyskij", 15.VII 1981 (D. Kasparyan), 1♀ [ ZISP]; Nature Reserve "Kedrovaja

Pad‘", 28.VI 1983 (A.Kirejtshuk), 1♂ [ ZISP]; Barabash-Levada, 5.VI 1979 (B.),

1♂ [ ZISP]; near Spassk, 30.VI 1985 (D. Kasparyan) , 1♀ [ ZISP]; Gornotaezhnoe ,

20 km SE Ussuriysk , 12.VII 1983 (E. Budrys) , 1♀ [ ZISP]; same, 25.VII 1983 (E.

Budrys), 1♀, 1♂ [ ZISP]; same, 4.IX 1983 (E. Budrys), 1♀ [ ZISP]; Ternej, 20.VI

1979 (B.), 2♀ [ ZISP]; Barabash, 5.VIII 1978 (D. Kasparyan) , 1♀ [ ZISP]; Shcher-

bakovka, 25.VII 1979 (B.), 1♀ [ ZISP]; Vladivostok, Okeanskaya, 23.VI 1937 (N.

Filippov), 1♂ [ ZISP]; same, 23.VI 1981 (D. Kasparyan), 2♂ [ ZISP] .

DESCRIPTION. FEMALE. Black; mandible (except apex), palps, antenna and legs yellowish brown, pronotal lobes whitish, metasoma apically brownish. Antenna,

femur and hind tibia wide darkened. Body length 3.8–4.4 mm (holotype 4.3 mm).

Head. Transverse, frons with weak median sulcus (in some specimens sulcus in-

distinct). Eyes distinctly converging downwards ( Fig. 10 ), ratio of minimal distance upper eyes to minimal distance between eyes 1.2 ×. Ocelli variable, enlarged in some specimens; in holotype, ratio POL/OOL 0.7 × ( Fig. 11 ). Frons slightly convex before anterior ocellus; temples roundly convex backwards (dorsal view). Clypeus with elongated central lobe, excised anteriorly; lateral lobes with weak, wide, rounded projections ( Fig. 10 ). Occipital carina well developed, disappearing below; head on underside with transverse fold, separating occipital fossa anteriorly, often in the form of an inflection ( Fig. 12 ). Mandible tridentate apically. Antenna simple, flagellomeres distinctly longer than its width. Palps strongly elongate. Head smooth and shiny,

with rare fine punctures; setation weak, setae gray, short and rare, longer on clypeal anterior border.

wing (arrow shows the position of m-cu); 8 – scutellum, metanotum and propodeum, dorsal view; 9 – labels.

lateral view). 10–12 – Stigmus eurasiaticus sp. n., ♀ (10, 11, holotype; 12, paratype, Primorskiy Terr.); 13–15 – S. convergens , ♀ ( Japan) .

Mesosoma. Pronotal collar transverse, with transverse carina and rounded angles;

anterior surface finely densely wrinkled; behind carina with rare longitudinal folds;

pronotal lobes reach tegula. Mesonotum with lateral admedian lines (holotype with median groove); notauli well developed, deeply impressed in anterior third; parapsids developed only in central part; median part, limited by notauli, usually matt, with microscopical irregular longitudinal wrinkles, sometimes with rugae, sloping towards the middle; lateral parts smooth and shiny; punctures small and rare.

Furrow between mesonotum and scutellum with short carinae. Scutellum with or without median sulcus, posteriorly with median tooth; punctures small and rare;

smooth and shiny. Metanotum anteriorly with short median dentiform carina; matt.

Epicnemium and upper part of mesopleuron gently rugose; triangular area (limited by postspiracular carina, omaulus, scrobal sulcus and hypersternaulus) and mesopleuron bottom, smooth and shiny. Propodeum with cellular sculpture, metapostnotum well separated ( Fig. 8 ). Setation weak, setae gray, shot and rare.

genitalia, ventral view.

Legs. Simple, protarsal comb not developed.

Wings. Venation of fore wing typical for Stigmus , veins and pterostigma brown;

hind wing media diverging after apex of anal cell ( Fig. 7 ).

Metasoma. Petiolus long, dorsally with two longitudinal ribs and with transverse folds; lateral surface with longitudinal ribs; length about 0.8–0.9 × length of metasomal tergum 1. Pygidial plate near flat, semielliptical, with short rounded apex.

Metasoma smooth and shiny; punctuation and setation weak, more dense on apical segments; pygidial plate matt.

MALE. Coloration as in females. Body length 3.6–4.4 mm.

Head. Transverse, frons with weak, but distinct median sulcus. Eyes distinctly converging downwards ( Figs 20, 22 ), ratio of minimal distance upper eyes to minimal distance between eyes 1.46–1.47 ×. Ocelli variable, enlarged in some specimens ( Figs 21, 23 ). Frons slightly convex before anterior ocellus; temples roundly convex backwards (dorsal view) ( Figs 21, 23 ). Clypeus slightly excised anteriorly. Occipital carina well developed, disappearing below; head on underside with transverse fold,

separating occipital fossa anteriorly, often in the form of an inflection. Mandible bidentate apically. Antenna simple, flagellomeres distinctly longer than its width.

Palps strongly elongate. Head smooth and shiny, with rare fine punctures; setation weak, setae gray, short and rare, on clypeus and adjacent part of frons dense, with silvery reflection.

Mesosoma, legs and wings as in females.

Metasoma. Petiolus long, length variable, 0.9–1.1× length of metasomal tergum

1; sculpture as in females. Subgenital sternum long, linear, with rounded apex;

laterally with strip of short dark bristles (lacking apically); apically with several long setae. Genitalia – Fig. 17 .

COMPARISON. A new species differs from Stigmus solskyi A. Mor. by smooth and shiny mesopleural triangle and lacking lateral excision at male clypeus; from S.

munakatai Tsuneki and S. pendulus Panzer differ by whitish pronotal lobes and venation of hind wing (M diverging after apex of anal cell) ( Fig. 7 ); from S.

quadriceps Tsuneki and S. japonicus Tsuneki by female head shape (more convergent temples in dorsal view), darkened femur and short digitus in male.

Stigmus eurasiaticus sp. n. is closely related with S. convergens Tsuneki but differs by head shape ( Figs 11 vs 14 and 21 vs 19); by ratio of minimal distance upper eyes to minimal distance between eyes (1.3 × in female and 1.53 × in male of S.

convergens); by weak longitudinal groove on the frons; by more densely wrinkled propodeum ( Fig. 8 ), by developed transverse fold, separating the occipital fossa anteriorly in female ( Figs 12 vs 15).

ETYMOLOGY. The specific name is adjective, with the reference to the wide distribution from Europe to the Far East.

DISTRIBUTION. Russia (Karelia, Nizhny Novgorod Prov, Mari El Rep.,

Chuvash Rep., Sverdlovsk Prov., Chelyabinsk Prov., Altai Rep., Irkutsk Prov.,

Khabarovsk Terr., Primorskiy Terr.).

Stigmus convergens Tsuneki, 1954: 33 , ♀, holotype, ♀, Japan, Hokkaido, Akagawa near

Kucchian [Museum of Nature and Human Activities, Hyogo, Japan]; Budrys, 1987: 52

(part., Kuril Ils.).

SPECIMENS EXAMINED. Russia: Kuril Ils.: Shikotan Il., 16, 20.VIII 1973

(D.R. Kasparyan), 2♀ [ ZISP]; Kunashir Il., 7 km N Mendeleevo , 2.VIII 1981 (B.),

1♀ [ ZISP]. Japan (1♀, 1♂) [ ZISP] .

DISTRIBUTION. Russia (South Kurils: Shikotan, Kunashir), China (Taiwan),

Japan (Hokkaido, Honshu). NOTE. It is island species which replaced on the main-

land by Stigmus eurasiaticus sp. n.

Figures

Figs 6–9. Stigmus eurasiaticus sp. n., holotype, ♀. 6 – habitus, lateral view; 7 – hind

Figs 10–15. Head of female (10, 13 – frontal view; 11, 14 – dorsal view; 12, 15 – ventro-

Figs 16,17. Stigmus eurasiaticus sp. n., ♂, paratype, Primorskiy Terr. 16 – habitus; 17 –

Figs 18–23. Head of male (18, 20, 22 – frontal view; 19, 21, 23 – dorsal view). 18, 19 – Stigmus convergens, ♂, Japan; 20–23 – S. eurasiaticus sp. n., ♂, paratypes, Primorskiy Terr.