Pachyanthidium (Trichanthidiodes) semiluteum Pasteels

Eardley, Connal & Griswold, Terry, 2017, Taxonomic revision of the Afrotropical species of Pachyanthidium Friese (Hymenoptera: Megachilidae: Anthidiini), Zootaxa 4237 (3), pp. 401-453 : 409-412

Pachyanthidium (Trichanthidiodes) semiluteum Pasteels

( Figs 4–6 )

Pachyanthidium (Trichanthidium) semiluteum Pasteels, 1981: 257 , male holotype (NHML) South Arabia; Pasteels 1984: 153. Pachyanthidium (Trichanthidiodes) semiluteum Pasteels : Michener and Griswold 1994: 319.

Pachyanthidium (Pachyanthidium) minutulum Pasteels, 1984: 149 , female holotype (AMGS) Somalia. Syn. nov.

Diagnosis. The combination of eyes hairy and T3–T5 without lateral spines separates this species from all other Pachyanthidium . Additional diagnostic characters include distinctive body markings ( Fig. 4 a-d), arolia absent and ocelli not reduced.

Description. FEMALE. Lengths: head 2.3 mm; scutum 1.3 mm; forewing 4.6 mm; body 5.5 mm. Head mostly yellow, frons black except for yellow mediolongitudinal stripe and anterior vertex ( Fig. 4 a). Mesosoma black except for yellow anterolateral and lateral margins of scutum, most of axilla, posterior half of scutellum, pronotal lobe and mesepisternum posterior to omaulus ( Fig. 4 b); legs yellow with basal regions (coxa, trochanter and basal femora) orangish-yellow. T1 yellow laterally, black mesally, T2–T4 with yellow cross-bands, black anteriorly and orange posteriorly; T5-T6 yellow; T1–T5 with translucent distal margins ( Fig. 4 b); S1–S6 blackish anteriorly, orange posteriorly. Structure ( Fig. 4 a, b). Preoccipital dorsal lamella short; eye hairy; clypeus ventral edge smooth, straight; mandible with 5 small teeth; pronotal lobe lamellate; omaulus lamellate; forebasitarsus short and broad, length half foretibia, half width; arolia present; T1–T5 without lateral spines ( Fig. 5 a); T6 carinate laterally, without spines, emarginate posteriorly ( Fig. 5 a).

MALE. Lengths: head 2.4 mm; scutum 1.4 mm; forewing 4.8 mm; body 6.1 mm. Colour as in female except T5 with yellow cross-band, black anterior and orange posterior margins, T6–T7 yellow ( Fig. 4 d). T1–T6 with translucent distal margins. Structure. Preoccipital lamella short; eye hairy; antennal flagellum length 1.2x eye length, 2.8x scape length; clypeus ventral edge smooth, straight; mandible 3–toothed; forebasitarsus sparsely pubescent, not distinctly fringed; hind basitarsus wide, length twice width; arolia absent; T1–T4 without lateral spines or swelling, T5–T7 with lateral swellings; T6 extended posteromedially, lamellate dorsolaterally, lobate ventrolaterally ( Fig. 5 b); T7 with broad posterolateral, inward curved spine and narrow median spine ( Fig. 5 b); S8, genitalia as illustrated in Fig. 5 c, d.

Distribution. Known from Kenya, Somalia, and Saudi Arabia ( Fig. 6 ). The type locality of P. semiluteum is Abou Arish, Saudi Arabia ( Pasteels 1981), which is near the southwest coast of the Arabian Peninsula and part of the Afrotropical Region. Therefore, it is not surprising that P. semiluteum would also be found on adjacent parts of Africa including the type locality of P. minutulum from Somalia ( Pasteels 1984).

Material examined. Type material. Male paratype of Pachyanthidium semiluteum : ‘ Afrika : Kenia Samburu 5.iv.1979 , PARATYPUS, Pachyanthidium (Trichanthidium) semiluteum N. SP. J. Pasteels det., 1982, COLL. MUS. TERVUREN Don J. Pasteels‘, RMCA. Female holotype of Pachyanthidium minutulum : ‘ Somaliland near Belet Uin 16/ii/63 Desert Locust Survey, Pseudoanthidium (Branthidium) minutulum Ckll J. Pasteels det., 1967 , HOLOTYPE ♀ Pachyanthidium minutulum Pasteels 1984 , 002595’, AMGS.

Additional material. Kenya. Archer’s Post, Uaso Nyiro River, 2300’, 1969 . xii.12, M. E. Irwin, E. S. Ross (1♀ 1♂ CAS); Coast Province , Taita Hill Discovery Centre, 2002. xii.13–14, M . A. Prentice (1♂ BBSL); Laisamis, 1969 . x.11, M. E. Irwin E. S. Ross (1♀ BBSL 827091); Archer’s Post, 1969. x.12, M. E. Irwin E. S. Ross (1♀ BBSL 827092); Kitani Lodge, Tsavo National Park, 1969. x.29, M. E. Irwin E. S. Ross (1♀1♂ BBSL 827087); Nyiro River, Archer’s Post Uaso, 1969. x.12, M. E. Irwin E. S. Ross (1♀ BBSL 827089 ) .

Discussion. The holotype of P. minutulum has hairy eyes and therefore does not belong to Pachyanthidium s. str. as indicated by Pasteels (1984). It is synonymous with P. semiluteum based on type study.

Figures

FIGURE 4. Pachyanthidium semiluteum Pasteels. a – b. Female. a. Face. b. Habitus. c – d. Male. c. Face. d. Habitus.

FIGURE 5. Pachyanthidium semiluteum Pasteels. a. Female metasoma, dorsal view. b – d. Male. b. T 6 – T 7. c. Distal region of S 8. d. Genitalia, dorsal view.

FIGURE 6. Pachyanthidium semiluteum Pasteels, known distribution.