Stenodynerus fastidiosissimus (de Saussure, 1855)

(Figs. 1B, 2A, 2C)

Odynerus Fastidiosissimus de Saussure 1855: 265, pl. XII fig. 7, ♀, ♂ (in subgenus Odynerus division Epsilon)—“L’Algérie ou l’Europe méridionale” (lectotype female MNHN [here designated]).

Nannodynerus vergesi Giordani Soika 1961: 373, fig. 1, ♂, ♀—“Spagna: Sagunto” (holotype male MSNVE).

Diagnosis. This species can be recognized by the following combination of characters: gena 0.85–1.0 (♀) or 0.75– 0.85 (♂) × as wide as eye at bottom of ocular sinus, occipital carina shortly lamellate and not delimiting a furrow; parategula curved and pointing behind; lateral carinae of propodeum present, transition between dorsal and lateral faces marked by an irregular but distinct margin; T1–T5 with yellow bands. In female: apical teeth of clypeus with short blunt carinae, apical margin of clypeus subtruncate; occipital carina of same height for whole length and almost straight; pronotal carina produced at extreme sides, pronotal humeri sharply right-angled in dorsal view; triangular lobes of submarginal carina largely yellow and with a broad translucent margin, about 0.5× as long as the distance between their bases; disc of S2 densely punctured, punctures arranged in transverse series and interspaces shorter than half puncture diameter; ocular sinus entirely black. In male: clypeus 0.9× as long as wide, apical margin wider than distance between toruli and emargination 0.3× as deep as wide, punctures on clypeus dense but nearly absent on upper fourth, rounded on dorsal half and elongate in dense irregular shallow striae on ventral half; F11 long and broad, reaching middle of F8 in lateral view, 2.3× as long as basally wide in dorsal view, flattened dorsoventrally and elliptical in section; S2 densely punctured, most interspaces narrower than puncture diameter, especially on lateral thirds, several punctures arranged in irregular transverse series; ventral lobe of aedeagus elongate, with rounded apex and a small denticle in lateral view

Material examined. LECTOTYPE Of ODYNERUS FASTIDIOSISSIMUS DE SAUSSURE: ♂, labeled “ O. fastidiosissimus / Sauss. / Algerie / Coll. St. Fargeau // [empty rounded blue label] // Museum Paris // MNHN, Paris / EY35883 [QR code] // Odynerus fastidiosissimus / de Saussure, 1855 / LECTOTYPE / Des. Marco Selis 2023” (MNHN, EY35883). HOLOTYPE Of NANNODYNERUS VERGESI: ♂, labeled “Sagunto / Valencia (Hispania) / GINER MARI / 25-VII-41 // Nannodynerus vergesi / Giordani Soika, 1961 / HOLOTYPE / Marco Selis vidit 2023” (MSNVE). ALGERIA: O. Ouchaia, 18.VI.1910, leg. J. Bequaert, 1♂ (MSVI, OR292157); Oran, leg. Schmiedeknecht, 1♀ (MSNVE); Oran, 1895, leg. Schmiedeknecht, 1♀ (MSNVE). CORSICA: Magnataja, 19.IX.1981, leg. Tussac, 1♂ (BGOF, OR292167). FRANCE: Alenya (P.O.), 15.IX.1966, leg. Nouvel, 1♀ (BGOF); Alenya (P.O.), 13.VII.1967, leg. Nouvel, 1♀ (BGOF); Banyuls (P.O.), 6.VI.1964, leg. Nouvel, 1♂ (BGOF); Banyuls (P.O.), 16.VII.1964, leg. Nouvel, 1♀ (BGOF); Banyuls (P.O.), 19.VII.1965, leg. Nouvel, 1♂ (BGOF); Cabanes de Fleury, Narbonne, 8.II.1970, leg. W. Aigner, 1♀ (MSVI, OR292162); Conques-sur-Orbiel, 11.VI.2005, leg. Bitsch, 1♂ (BGOF, OR292160); Ferralsles-Corbières, 28.V.2009, leg. Bitsch, 1♀ (BGOF); Grabels, 23.V.1985, leg. B. Gereys, 1♂ (BGOF); Le Barcarès (P.O.), 13.VII.1966, leg. Nouvel, 1♂ (BGOF); Provence, Cavalaire s.M., 29.VIII.1936, leg. Naef, 1♀ (MSNVE). MOROCCO: Beni Mellal, 21.VI.1974, leg. J. de Beaumont, 1♀ (MSNVE); Casablanca, 15–31.VIII.1918, leg. Benoist, 1♂ (MSNVE); El-Menzel, 30 km E Sefrou, 29.V.1995, leg. M. Halada, 1♂ (OLML); Fedhala, Oued Nefifik, 26.VIII.1935, leg. Naef, 1♀ (MSNVE); Fès-Meknès, Azrou, P7311, 10 km S Ain Leuh, 1750 m, 33.2220 -5.3411, 17.V.2022, leg. T.J. Wood, 1♂ (MSVI, OR292156); Ifrane, Mischliffer, 2200 m, 22.VI.2002, leg. P. Rosa, 3♀ (MSVI); Port Lyautey, 25.V.1947, leg. Naef, 1♂ (MSNVE); Tadla-Azilal, Demnate 3km E, 1080 m, 31.724444 - 6.966111, 4.V.2015, leg. V. Soon, 2♂ (TUZ, 034231; TUZ034229, OR292159); Tadla-Azilal, Demnate 3 km E, 1080 m, 31.724722 -6.965278, 8.V.2015, leg. V. Soon, 1♀ (TUZ036159, OR292158); 10 km W Tiznit, 6.V.1995, leg. M. Halada, 1♀ (OLML). PORTUGAL: Algarve, Alte, 9.IX.1980, leg. J. Teunissen, 1♀ (MSNVE); Algarve, Carrapateira, 17.IX.2015, 3♂ (MSVI, 1♂ OR292169); Algarve, Monchicque, 1.IX.1980, leg. J. Teunissen, 1♂ (MSNVE); Algarve, Praia do Barril, 24.IV.2016, 1♂ (MSVI, OR292170); Algarve, Salema, Boca do Rio, 16.IX.2015, 1♀ (MSVI, OR292168); Algarve, Salema, Boca do Rio, 19.IX.2015, 1♀ (TJWC); Caparica, 12.VI.1952, leg. N.F. de Andrade, 1♀ (MSNVE); Caparica, 13.V.1952, leg. N.F. de Andrade, 1♀ (MSNVE); Estremadura, Sao Martino do Porto cliffs, 16.IX.1969, 1♂ (MSNVE); Fontanelas, 9.IX.1953, leg. N.F. d’Andrade, 1♂ (MSNVE); Pera Dunes, 18.IX.2015, 1♂ (TJWC). SPAIN: Barcelona, Sitges, 20.VI.2006, leg. L. Fancello, 1♀ (MSVI); El Tranco, 28.V.1968, leg. Vergés, 1♂ (MSNVE); Huelva, El Rocio, 4.VIII.1967, leg. P.M.F. Verhoeff, 1♀ (MSNVE); Iberia sept.or., Playa de Aro, Costa Brava, 20.IX.1975, leg. P. Ploch, 1♂ (MSNVE). TUNISIA: Manouba, Eddekhila, 36.868333 9.599167, 1.X.2019, leg. M. Romano, 1♀ (MSVI).

Distribution. Algeria, France (including Corsica), Morocco, Portugal, Spain (including Balearic Islands), Tunisia (Baldock 2014; Baldock et al. 2020 a, 2020b; Blüthgen 1953, 1956a, 1956b; Castro 1986, 1989, 1992; Castro & Sanza 2009; Giordani Soika 1953b, 1961, 1966; Gusenleitner 1981, 2000; Tussac 2007; Verges-Serra 1967) (Fig. 6A).

DNA barcoding. COI-5P gene sequences were obtained from ten specimens from Morocco, Algeria, France, and Portugal. The mean intraspecific sequence divergence of S. fastidiosissimus is 2.87%, with IberoMaghrebian specimens differing from French specimens by 5.69–6.73% (mean 6.14%), a gap probably caused by the unavailability of sequences from the eastern part of the Iberian Peninsula. The species is clearly separated from the other taxa considered in this study and supported by a bootstrap value of 100 (Fig. 6B). The lowest interspecific genetic distance exists between S. fastidiosissimus and S. muelleri, with a minimum of 21.85% (mean 23.37%).

Notes. The interpretation of this taxon has been incorrect for a long time, at least since the description of Nannodynerus vergesi Giordani Soika, 1961. Giordani Soika (1961) applied the name fastidiosissimus to French and Italian populations characterized by emarginate clypeus, smaller F11 of the male and subtriangular ventral lobes of aedeagus, contrasting the newly described vergesi which was characterized by a subtruncate clypeus, larger F11 of the male, and rounded and toothed ventral lobes of aedeagus. These two names have been used this way in several subsequent publications (e.g. Castro 1986, 1989, 1992; Giordani Soika 1966, 1979; Gusenleitner 1981), even in the synonymy made by Castro & Sanza (2009), who considered these differences as variability. Examination of the type series of S. fastidiosissimus, housed in the MNHN and comprising three female specimens (one from Algeria, a damaged one from southern France, and one without data), showed that it does not match with S. fastidiosissimus sensu Giordani Soika (1961), but instead with S. vergesi. For this reason, the name fastidiosissimus is to be applied to the populations showing the characters listed in the diagnosis above and occurring in France, the Iberian Peninsula and western North Africa, that were formerly known as S. vergesi; this name is confirmed as a junior synonym. In order to provide a quality reference for this species, the undamaged and labelled specimen from Algeria is designated as a lectotype (Fig. 2A).

The original description of Nannodynerus vergesi (Giordani Soika 1961) reported the holotype and an unknown number of paratypes to be housed in the Giordani Soika collection, but they were not found during its recent reorganization (cf. Dal Pos et al. 2022). The holotype is in fact found in the Giordani Soika collection, but was not recognized as it lacks any label identifying it as a type. Examination of the material housed in MSNVE revealed the presence of a male specimen labelled with the same data reported by Giordani Soika (1961: 375; “ Spagna: Sagunto, 1♂ il 25-VII-41 (Giner Mari—olotipo—m.coll.)”), matching in all aspects with the original description and lacking genitalia, as they were used to image the aedeagus in the description (Giordani Soika 1961: 374, fig. 1). The genitalia are missing but, as reported by Dal Pos et al. (2022: 4), Giordani Soika’s management of genitalia slides was quite chaotic. The mentioned specimen can be recognized as the holotype of Nannodynerus vergesi and is shown in Fig. 2C. A red label was placed beneath the specimen to allow future recognition.

Stenodynerus fastidiosissimus and S. difficilis seem to coexist in southern France according to literature (Gusenleitner 2000; Tussac 2007) and our examined material (Fig. 6A). As already reported under S. difficilis, it is possible that part of the records published by Berland (1928) may refer to S. fastidiosissimus.