Megachile leucostoma Pérez 1907

Praz, Christophe, Al-Shahat, Ahmed M. & Gadallah, Neveen S., 2021, Taxonomic revision of the subgenus Eutricharaea Thomson in Egypt, with a key to the species and the description of two new species (Hymenoptera, Anthophila Megachilidae, genus Megachile Latreille), Zootaxa 5032 (3), pp. 301-330 : 306-307

Megachile leucostoma Pérez 1907

Figs 5–7 .

Megachile leucostoma Pérez 1907: 489 , ♂, “ Dibba [ Oman]”. Holotype ♂, MNHN.

Megachile submucida Alfken 1926: 126 , ♀, ♂ partim, “Kingi [Maryut, sw von Alexandria; Egypt]”. Lectotype ♀, by designa- tion of Zanden (1986: 66; see below), SMFD. New synonymy.

Megachile microxantha Cockerell 1937: 205 , ♂, “ Aden [ Yemen]”. New synonymy. Holotype ♂, BMNH.

Megachile privigna Rebmann 1968: 40 , ♂, “ Fayed [ Egypt]”. Holotype ♂, SMFD. New synonymy.

Type material: The holotype ♂ of M. leucostoma was examined. The apically simple gonostylus, diagnostic for the M. concinna species complex, is visible and confirms that this name is the oldest available name for the taxon of the concinna complex present in the Arabian Peninsula and in northeastern Africa ( Soltani et al. 2017).

The holotypes ♂ of M. microxantha and of M. privigna were also examined; in both cases the apically simple gonostylus confirms the identity of these specimens.

Numerous syntypes of M. submucida (SMFD, ZMHB) were examined, including a pair labeled as types (considered here to be paratypes) from “Maadi” in ZMHB. Alfken (1926: 103) indicates that the type was from “Kingi, collection Andres”, with the reference number “Hymenopt. Nr 10” and deposited in the Senckenberg Collection. For this reason, we treat the “ holotype ” female referred to by Zanden (1986: 66), labeled “K. IX.13 [presumably Kingi, September 1913]” and “SMF-H10 [likely referring to type Hymenopt. Nr. 10]”, deposited in SMFD, as a lec- totype, since Alfken mentions “Beide Geschlechter [Both sexes]” from Kingi. We examined this female specimen and it agrees with the species of the M. concinna -complex known from Egypt.

Notes: The status of M. modestissima Dalla Torre 1896 , a replacement name for Megachile modesta Smith 1879 (not M. modesta Smith 1862 ), described from the “ White Nile ” [probably Sudan], is unclear; this name may apply to an African form of the concinna complex such as M. venusta Smith 1853 .

The status of M. striatella Rebmann 1968 requires further investigation since the type series appears to be mixed.

Additional material: EGYPT: 1 ♀, Marsa Matrouh ( North Coast ), 26.vii.1964, leg. Fathy (sweep net) ( PPDD) ; 1 ♀, Ismailia, 7.x.1984, leg. Tawfik ( PPDD) ; 1 ♂, Shubra ( Qalyubiya ), 3.vi.1916, leg. Qdair ( ASUA) ; 3 ♀, Maadi (Cairo), 8.x. 1953 ( ASUA) ; 2 ♀, Wadi Hoff (Cairo), 8.x.1953 ( ASUA) ; 1 ♀, Gabal el Asfar ( Qalyubiya ), 8.vii.1953, leg. Aly ( ASUA) ; 1 ♂, Pyramids (Giza), 24.vii. 1953, leg. Aly ( ASUA) ; 1 ♂, Gabal el Asfar ( Qalyubiya ), 8.vii. 1953, leg. Aly ( ASUA) ; 2 ♂, Khatatbah ( Minufiya ), 7.viii.1953, leg. Aly ( ASUA) ; 2 ♂, Suez (Ismailia), 17.ix.1953 ( ASUA) ; 1 ♂, Kharga Oasis (New Valley, Western Desert ), 8.v.1918 ( AUCE) ; 1 ♂, Cairo, 1932 ( AUCE) ; 1 ♂, Far- askur ( Damaietta ), 26.ix.1913, leg. Storey ( EFC) (all as M. submucida ) ; 3 ♀ 3 ♂, Luxor, Westbank of Nile River , 25.694N, 32.628E, 1.iv.2018, leg. C. Schmid-Egger ( CES, CPCN) ; 10 ♀ 2 ♂, Hurghada, Arabella Azur Resort , 27.240N, 33.848E, leg. C. Schmid-Egger ( CES, CPCN) ; UNITED ARAB EMIRATES: 4 ♀, Ain Al Waal, Al Ain, Jebel Hafeet W, 24.0677N, 55.75E, 13–26.iv.2015, leg. H. Roberts ( HRCA, CPCN, SDEI) ; see additional records in Soltani et al. (2017: Table S1).

Distribution: Oman, UAE, Yemen, Israel and Palestine, Jordan, Egypt; possibly Libya (see Soltani et al. 2017).

Diagnosis: Female: Very similar to M. leachella . Both species are characterized by features of the leachella - group ( Praz 2017), especially the absence of fovea laterally on T2 and T3 and the short occipital distance. In contrast to M. leachella , M. leucostoma has a narrowly emarginate apical clypeal margin ( Fig. 7 ; in M. leachella , apical margin more widely emarginate); the disc of T6 has reduced white vestiture, forming a diffuse spot of white hairs or at most two very small and reduced spots of white hairs (see note on geographic variation below), contrasting with the large spots of hairs in M. leachella . The scopa is often at least partly orange on S6 or on S5 and S6, sometimes also on S3 and S4. Some geographic variation is observed in the coloration of the vestiture ( Soltani et al. 2017): on the Arabian Peninsula, as well as in Southern Israel and on the Sinai Peninsula, the scopa is extensively orange and the white vestiture on the disc of T6 is more extensive; these specimens have been referred to as M. venusta (e.g., Alfken 1934), but this Afrotropical species is considered to be absent from the Palearctic region ( Soltani et al. 2017); in Northern Egypt west of the Nile, the scopa is white, sometimes weakly orange on S5 and S6, and the white vestiture on the disc of T6 is strongly reduced.

Male: Males of all species in the concinna complex are highly similar; they share with M. leachella the presence of an acute tooth under the base of the mandible; this tooth is best visible in front view when the mandibles are closed ( Fig. 6 ). Males of M. leucostoma differ from those of M. leachella by the simple gonostylus ( Fig. 5 ) (gonostylus with preapical lobe in M. leachella ; Praz 2017: fig. 56); specimens of these two species with the genitalia not exposed cannot be separated.

For now, all specimens of the concinna complex from Egypt are considered to belong to M. leucostoma ; it is not impossible, however, that future studies will confirm the presence of other forms, such as M. pusilla Pérez 1884 , which is present in northwestern Africa.

Figures

FIGURES 2–8. 2. Female of Megachile soikai, dorsal view. 3. Female of M. soikai, capitate hairs on underside of hind femur. 4. Male genitalia of M. soikai. 5. Male genitalia of M. leucostoma. 5. Head in front view of male of M. leucostoma, showing the distinct tooth behind the base of the mandible. 7. Clypeus of female of M. leucostoma. 8. Female of Megachile walkeri, dorsal view. 9. Clypeus and mandibles of female of M. walkeri. 10. Male genitalia of M. walkeri (left, dorsal view; right, lateral view).