Stenodynerus difficilis (Morawitz, 1867)

(Figs 18–25)

Odynerus difficilis Morawitz, 1867: 132, ♀, ♂ (in subgenus Leionotus) (holotype, ♀, deposited in Zoological Institute, St. Petersburg, Russia; type locality: “ Gouvernement von Saratow ” [Russia, Saratov Prov.]).

Odynerus proximus Morawitz, 1867: 128, ♀ (lectotype, ♀, deposited in Zoological Institute, St. Petersburg, Russia; type locality: Gouvernement von Saratow [Russia, Saratov Prov.]).

Odynerus insularis André, 1883: 232, ♀, ♂ (in subgenus Lionotus) (lectotype deposited in Muséum d’Histoire Naturelle, Neuchâtel, Switzerland; type locality: Sicile, Italy) [junior primary homonym of Odynerus insularis Smith, 1859].

Odynerus insulicola Dalla Torre, 1894: 74 . Replacement name for Odynerus insularis André, 1883 . Junior primary homonym of Odynerus insulicola Blackburn in Blackburn & Cameron 1886.

Odynerus maroccanus Dalla Torre, 1889: 125 . Replacement name for Odynerus insularis André, 1883 .

Odynerus ferrugineitarsis de Stefani, 1889: 232, ♀, ♂ (types probably destroyed; type locality: Sicile, Italy).

Nannodynerus fastidiosissimus difficilis: Blüthgen 1939: 250, 251, nos. 38, 39 (synonymy); 1959a: 270; 1959b: 149 ( difficilis differs from western Mediterranean fastidiosissimus), 150, nos. 6 and 7 ( ferrugineitarsis a form of difficilis).

Pseudepipona fastidiosissima: Giordani Soika 1952: 381, fig. 2 (1). Misidentification.

Nannodynerus ferrugineitarsis: Blüthgen 1964: 94.

Nannodynerus difficilis: Gusenleitner 1966: 349; Blüthgen 1967: 233.

Stenodynerus difficilis: Giordani Soika 1970: 108; van der Vecht & Fischer 1972: 66.

Stenodynerus difficilis ferrugineitarsis: van der Vecht & Fischer 1972: 66 (cat.).

Stenodynerus fastidiosissimus difficilis: Gusenleitner 1981: 209, 263 (syn.: ferrugineitarsis); 2007: 107; Castro & Dvořák 2009: 299.

Stenodynerus difficilis: Selis et al. 2024: 38 (stat. resurr.)

Material examined. China: 1♂, Xinjiang Uighur Autonomous Region, Börtala Mongol Autonomous Prefecture, Bole City, 44°38′27″N, 81°18′36″E, 4.VII.2023, Zhizhi Liu (CNU) .

Diagnosis. Female and male. Body length: female 7.0–10.0 mm, male 7.0–7.8 mm; black, following parts yellow (Fig. 18): clypeus entirely, mandible largely, scape ventrally, ocular sinus, interantennal spot, a small spot on upper gena, two large separated spots on pronotum anteriorly, tegula, anterior part of metanotum, apical bands on T1–T6 and S2, and legs largely. Clypeus in female wider than long, in male as wide as long and more sparsely punctate (Fig. 19); apex of clypeus with deep and rounded emargination and a short translucent margin in male (Fig. 19); male A13 hooked backward extending to the base of A11 (Fig. 20); anterior surface of pronotum (Fig. 21) vertical, with a few small punctures and a pair of round separated foveae, the interspace between the two foveae more than one fovea diameter, the foveae considerable variability and with the capacity to converge in a V-shaped pattern; propodeum medially without a transverse plane behind metanotum, posterior surface concave with transverse rugae (Fig. 22). T1 2× as wide as long; apical border of T2 obtusely bent, preapical portion of T2 forming narrowly impressed (Figs 23, 24); anterior surface of S2 sloping, in lateral view S2 rounded (Fig. 23), S2 with sparser punctures than T2, and ventrally in basal portion without a median longitudinal groove (Fig. 25).

Distribution. * China (Xinjiang), France (including Corsica), Italy (including Sicily), Malta, Greece, Croatia, Bulgaria, Turkey, Iran, Kazakhstan, Turkmenistan, Russia (European Part, Urals, Western Siberia) (Selis et al. 2024).