Calymmochilus atratus Fusu & Askew & Ribes 2018, stat. rev.

Calymmochilus atratus Masi, 1919 stat. rev.

Figs 1, 9, 10, 13, 15, 17 (♀), 2, 18, 58, 63, 70, 71 (♂)

Calymmochilus atratus Masi, 1919: 328 –330. Lectotype ♀ (present designation), MCSN, examined by LF. Type locality: Italy, Tuscany, Giglio Is.

Calymmochilus atratus; Erdős 1960: 230. Bouček & Andriescu 1967: 238 (distribution). Bouček, 1970: 81 (synonym of C. subnubilus).

Diagnosis. Female. Macropterous. Mesosoma and head concolorous, dark brown with weak metallic lustre (Fig. 1); gaster mostly brown except for partly white to hyaline Gt1. Legs and scape brown-yellow to variably darkened but at least following brown: meso- and metacoxae, profemur on posterior and metafemur on anterior surface, scape basally and apically on dorsal and outer surfaces. Head not conspicuously modified, convex, with lower parascrobal region passing smoothly into gena (Figs 9, 10). Clypeus protuberant, convex, apically serrate (Fig. 9). Scrobal depression deep, with sloping, non-carinate sides, smooth and shiny except for superficially sculptured scrobes and reticulate along outer margins (Figs 9, 10). Frontovertex between ocellar triangle and scrobal depression reticulate (Figs 9, 10). Mesoscutum reticulate virtually to posterior margin (Fig. 13). Mesoscutellum and axillae differentiated and distinct, scutellum slightly convex (Fig. 13). Acropleuron reticulate. Fore wing in larger specimens comparatively uniformly infuscate from base to apex (Fig. 15).

Male. Body brown with weak violet lustre visible under some angles of illumination (Fig. 2). Head in exact dorsal view (Fig. 71) 4.5–4.7× breadth of an eye measured along a transverse axis as in figure 73. Frontovertex between ocellar triangle and scrobal depression partly reticulate, with cells slightly depressed mesally or/and imbricate (Fig. 70). Scrobal depression including scrobes smooth and shiny except for superficially sculptured outer margins (Fig. 70). Funicle with first segment plus strongly reduced anellus 2.2–2.5× as long as wide (Fig. 63). Mesoscutal midlobe reticulate to, or almost to, posterior margin, though less distinctly so in small specimens; lateral lobe reticulate (Fig. 18). Mesoscutellum coriaceous except reticulate near anterior margin and imbricate to indistinctly reticulate laterally. Metascutellum transverse-ovoidal, with lateroventral corners abruptly sunken (cf. Fig. 68). Fore wing stigma as an elongated rectangle; uncus frequently almost to fully as long as height of stigma (Fig. 58).

Remarks. Females of C. atratus are very similar to those of C. subnubilus except for the sculpture of the head and mesoscutum, and fore wing infuscation pattern. Apart from these differences, which are detailed in the key, we did not find any other characters that could be used to distinguish the two species. The acropleuron is more strongly reticulate in C. atratus females compared to C. subnubilus, however this is difficult to quantify or use as an identification feature without comparative material at hand. Initially we considered the differences in sculpture as intraspecific variation for the following reason. The selected lectotype of C. atratus is the smallest specimen (2.2 mm) in the original series of three specimens. The other two specimens are larger, but their heads and various appendages were dissected by Masi, mounted separately but on the same card as the specimen, or on a card below it, and used to produce the illustrations in the original description. In addition to size, the lectotype differs from the other two specimens in the sculpture of its frons, and this is probably because it is slightly smaller. The frontovertex between the scrobal depression and the ocellar triangle is primarily coriaceous (cells or areoles delimited by engraved lines) to imbricate-coriaceous, but most of the cells are slightly to obviously depressed mesally so that the sculpture becomes reticulated (Fig. 9). The scrobal depression is smooth with the scrobe superficially and indistinctly coriaceous above the torulus, and imbricate-coriaceous to reticulate along the outer margins. The two paralectotypes have the frons clearly reticulate because all the cells are obviously sunken and separated by ridges, and the scrobal depression is also reticulate along the outer margins, while the scrobe above torulus is more evidently coriaceous compared to the lectotype.

1. One extremely small (1.1 mm) male from Morocco identified as this species based on head proportions, stigma and metascutellum shape has the scrobal depression polished in dorsal half, though ventral half is still sculptured.

We concluded that C. atratus is a species distinct from C. subnubilus only after examining syntopic series of specimens of both species in the Jean-Yves Rasplus (CBGP) and Gérard Delvare collections (GDPC). These show no transition between the two sculpture types. The difference in sculpture as a diagnostic feature is further supported by correlated fore wing colour patterns. Most females with reticulate sculpture have an almost clear to comparatively uniformly infuscate fore wing (C. atratus) (Figs 15, 17), whereas most females with coriaceous sculpture have fore wings that are comparatively more strongly infuscate behind the marginal and stigmal veins resulting in a central spot with diffuse limits (C. subnubilus) (Fig. 16). However, by itself the difference in infuscation is not very useful because some females of C. subnubilus with somewhat lighter infuscation are similar to C. atratus, and smaller females of both species have the wings essentially clear.

The lectotype of C. atratus has clear wings except for a slight basal infuscation (Fig. 17). The paralectotypes might have the wings slightly yellowish on the disk, but this is hard to appreciate because the wings are either glued to the card with a yellow-brown adhesive, or they can be examined only against the yellow paper of the card. However, they were described by Masi (1919: 328) as flavo-griseis.

The lectotype of C. subnubilus has both wings glued to the card and their colour is difficult to assess, but besides the darkened base it definitely has an infuscate spot with diffuse margins behind the marginal and stigmal veins (Fig. 7). The series of females from France and Canary Islands have the same wing pattern, with the wing mostly hyaline behind the submarginal vein and parastigma, and at the apex, but with a brown spot with diffuse margins behind the stigmal vein and apical two-thirds of the marginal vein. The females in the series from Greece, however, have the wings either hyaline except for the base in the smallest specimens, or with a variably intense and rather uniform yellowish hue on the disk with the infuscate spot barely distinct and hence more similar in this respect to C. atratus.

Differences in sculpture of the same magnitude as those mentioned above are used to distinguish good biological species in the genus Eupelmus Dalman (Chalcidoidea, Eupelmidae) (Al khatib et al. 2014; Gibson & Fusu 2016; Fusu 2017).

The males of the two species are difficult to separate because the main differentiating character is sculptural. Similar to females, the head and mesoscutum are coriaceous in C. subnubilus males and reticulate and/or imbricate-coriaceous in part in C. atratus males as detailed in the key. Small males have effaced sculpture and the differences between sculpture types fade. The other difference mentioned in the key, the length of the first funicular segment, might prove not to be reliable when more specimens become available.

Distribution. Because the species was considered a synonym of C. subnubilus since 1970, some records of C. subnubilus after this date could have been based on misidentified C. atratus.

Since the two species are so similar, the record of C. atratus from Algeria (Bouček & Andriescu 1967) needs verification. It was made before the correct placement of Eupelmus subnubilus in Calymmochilus became known, its type being examined by Z. Bouček in 1969 (Bouček 1970).

The species seems infrequent compared to C. subnubilus and besides the types from Giglio Island in Italy we have seen specimens from South France including Corsica and from Spain (new records).

Material examined. Type material. ITALY: Lectotype ♀ of Calymmochilus atratus (present designation): “ Is. Giglio / v.1901 / G. Doria | Calymmochi / lus atratus / Ms./ ♀ Cotypus! | SYNTYPUS ♀ / Calymmochilus / atratus / Masi, 1919 | Museo Civico/ di Genova | LECTOTYPUS / Calymmochilus / atratus Masi / Det. Fusu L. 2017” (MCSN). Paralectotypes, 2♀: “ Is. Giglio / i.1902 / G. Doria | Calymmochi / lus atratus / Ms./ ♀ Cotypus! | SYNTYPUS ♀ / Calymmochilus/ atratus/ Masi, 1919 | Mus. Civ./ Genova” (1♀ MCSN). “ Stazzano / viii.85 / Ferr [original label] | Stazzano Scrivia / viii.1885 / P.M. Ferrari [newer label] | Calymmochi / lus atratus / Ms./ ♀ Cotypus! | SYNTYPUS ♀ / Calymmochilus / atratus / Masi, 1919 | Museo Civico/ di Genova” (1♀ MCSN).

Non-type material. FRANCE: Hérault, St Guilhem le Désert, 1.vi.1990, Rasplus (1♀ 1♂ CBGP, ♂ with no.

2017-28). Hérault, Joncels, D138, 10.x.1995, Rasplus (1♀ CBGP). Hérault, Baillarguet, PT&MT, 43°42’18’’N, 3°53’E, 30.vi–19.vii.1995, pine/oak for., P. G. Mason (1♂ CNC). Pignans (Var), 3.ix.1966, J. Barber (1♀ CBGP). Pyr. Orie., Le Rimbeau, 31.vii.1991, Rasplus (1♀ CBGP). Hérault, Saint-Martin-de-Londres, 43.776244°N 3.721428°E, ix.1997, Malaise trap, J.Y. Rasplus no. 1441 (1♀ CBGP). Grabels, 20.ix.1997, Meusnier (1♂ CBGP). Hérault, Montpellier, SIGMA, piège Malaise, 15–21.ix.1988, G. Delvare (2♂ GDPC). Alpes Maritimes, Sophia- Antipolis, 43.616067°N 7.062825°E, 25.vii.2015 (M. Viciriuc) (1♂ AICF). Alpes Maritimes, Sophia-Antipolis, 43.615527°N 7.061395°E, 27.vii.2015 (M. Viciriuc) (1♂ AICF). FRANCE (CORSICA): Manso, 200 m, vallon du Perticatu, 42°23’N 08°45’E, piège jaune, 16.v.1992, Andréi-Ruiz M. -C. (2♀ GDPC, one no. 2017-18). Manso, 200 m, maison forestière Pirio, 42°23’N 08°45’E, piège Malaise, 10-17.ix.1997, Andréi-Ruiz & Villemant (1♀ GDPC). SPAIN: Madrid, El Ventorillo, 1480 m, 1–6.vi.1990 (1♀ CNC).