Megachile argentata argentata (Fabricius, 1793)

Praz, Christophe J. & Benon, Dimitri, 2023, Revision of the leachella group of Megachile subgenus Eutricharaea in the Western Palaearctic (Hymenoptera, Apoidea, Megachilidae): A renewed plea for DNA barcoding type material, Journal of Hymenoptera Research 95, pp. 143-198 : 143

Megachile argentata argentata (Fabricius, 1793)

Apis argentata Fabricius, 1793: 336 [sex not indicated], "in Barbaria" [Algeria or Tunisia]. Lectotype ♀ (NHMD), by designation of Hurd (1967).

Megachile compacta Pérez, 1895: 24, ♀, [Algeria]. Preoccupied, not Megachile compacta Smith, 1879. Lectotype ♀ (MNHN), by present designation (see below). New Synonymy.

Megachile crassula Pérez, 1896: 1. Nomen novum for M. compacta Pérez. New synonymy.

Perezia maura Ferton, 1914: 233, ♀ [gynandromorph specimen], "Cimetière de Djidjelli" [Jijel, Algeria]. Holotype intersex (MNHN). Preoccupied, not Megachile maura Cresson, 1865. Synonymy with M. centuncularis in Pasteels (1969: 248). Synonymy with M. leachella in van der Zanden (1988: 56). New synonymy.

Megachile pilidens Alfken, 1924: 88, ♀ ♂, "Triest [Trieste, Italy]". Lectotype ♀ (ZMHB), by designation of Tkalců 1967: 100. New synonymy.

Megachile argyrea Cockerell, 1931: 275, ♀ ♂, "Asni [Morocco]". Holotype ♀ (USNM), paratypes ♀ ♂ (BMNH). New synonymy. Synonymy with M. pilidens in Hedicke, 1933: 42.

Material examined.

Type material. Lectotype ♀ of M. argentata (NHMD) (Figs 1 - 3 ; see above, identity of type specimens).

Lectotype ♀ of M. crassula (MNHN), by present designation, a female in good condition labeled as follows: 1. “Algeria” [printed]; 2. Megachile crassula JP [handwritten, presumably by Pérez]; 3. " Museum Paris Coll. J. Pérez” [printed on blue paper]; 4. " Holotype M. crassula des. Baker 1991" [printed and handwritten on red paper]; 5. " Lectotype M. crassula des. C. Praz 2022". Although the original description does not mention the number of specimens, we prefer to designate this specimen as the lectotype.

Holotype [gynandromorph] of Perezia maura (MNHN), labeled as follows: 1. "Djidjelli 17-8/ 13 p. 315" [handwritten by Ferton]; 2. " Perezia maura ♀ Fert" [handwritten by Ferton]; 3. Holotype [printed, red]; 4. Muséum Paris Ch. Ferton 1902 [printed, blue paper]; 5. Megachile pilidens Alfken [symbol for gynandromorph] det. G.v.d. Zanden 1986; 6. " Perezia maura Ferton = gynandromorph de Megachile centuncularis J. Pasteels det., 1969"; 7. Megachile argentata intersex det C. Praz 2022. It is unclear why van der Zanden (1988) placed this taxon in synonymy with M. leachella since the label on the specimen suggests he correctly identified the holotype as M. pilidens .

Lectotype ♀ of M. pilidens (ZMHB). A female without metasoma, but clearly identified as M. argentata (see Tkalců 1967).

Paratypes ♀ and ♂ of M. argyrea (BMNH), all in good condition and clearly corresponding to M. argentata . We did not examine the holotype ♀ of M. argyrea , but pictures are available at https://collections.nmnh.si.edu/search/ento/; based on these pictures, the holotype agrees with M. argentata in the dark vestiture of the lateral parts of T5 (absent in M. leachella albipila and M. inexspectata ). Punctation of the vertex is not visible but the dense punctation of the terga appears to exclude M. leachella albipila . This character and the identity of examined male and female paratypes (BMNH) collected in the same site confirm synonymy with M. argentata.

Note.

Megachile beaumonti Benoist, 1951, is currently treated as a synonym of M. crassula ( van der Zanden 1990: 53). We have examined the holotype ♀ of this taxon (MZL); Megachile beaumonti is not conspecific with M. argentata , but is a valid species of the Megachile rotundata group (stat. rev.).

Other material.

216 specimens from the following countries: Croatia, France, Germany, Greece, Iran, Italy, Kyrgyzstan, Lebanon, Morocco, Northern Macedonia , Portugal, Russia, Serbia, Spain, Switzerland, Tunisia, Turkey, Ukraine (Suppl. material 1) .

Distribution.

Widespread and abundant in southern Europe; in expansion in central and northern Europe, e.g., in northern Switzerland (C. Praz et al., in prep.), the Netherlands ( Peeters et al. 2006) and Germany (LUBW 2007; Schweitzer and Theunert 2019). Present in the Levant (Turkey, Lebanon), but so far its presence has not been confirmed in Israel and Egypt ( Praz et al. 2021). We have examined specimens from Rhodos, Lesvos, Samos, Karpathos, Patmos, Chios, but neither from Cyprus [the record of M. pilidens by Varnava et al. (2020) is probably an identification error and likely refers to M. leachella densipunctata ssp. nov.] nor from Crete. Further east, the species is present in Iran, Armenia and Kyrgyzstan.

Geographic variation.

Geographic variation has been discussed above in detail. The northwestern African populations, as well as populations from the Island of Pantelleria, have overall snow-white vestiture in the female sex (Fig. 15 ) and dark vestiture on the mesonotum and vertex, and in the male sex a continuous fringe of hairs on the margin of T6. On the Island of Karpathos, the female scopa is orange on S5 and S6, approaching the condition observed in M. argentata schmiedeknechti .

Figures

Figure 1. Vertex of the lectotype female of Megachile argentata (Fabricius, 1793), showing the ocelloccipital distance OOD (yellow line), two tangentials placed behind the lateral ocellus and along the inner margin of the compound eye (red lines), and the white rectangle with dimensions 1.1 x OOD x 0.55 x OOD within which the punctures were measured in our morphometric analyses.

Figures 2, 3. Lectotype female of Megachile argentata 2 dorsal view 3 head in front view.

Figures 15 - 24. Megachile argentata 15 female metasoma of northwestern African populations, M. argentata argentata 16 female metasoma of European, Levant, Turkey and Central Asian populations, M. argentata argentata 17 female metasoma of Malta populations, M. argentata schmiedeknechti 18 female metasoma of Corsican and Sardinian populations, M. argentata schmiedeknechti 19 female metasomal tergum 4 20 female vertex 21 apex of female clypeus 22 male front tarsi 23 male metasomal sterna 3 - 5 24 male genitalia.