Thyreus shebicus Engel

Alqarni, Abdulaziz S., Hannan, Mohammed A. & Engel, Michael S., 2014, A new species of the cleptoparasitic bee genus Thyreus from northern Yemen and southwestern Saudi Arabia (Hymenoptera, Apidae), ZooKeys 428, pp. 29-40 : 30-35

Taxon classification Animalia Hymenoptera Apidae

Thyreus shebicus Engel sp. n. Figs 1-11

Holotype.

♂, N. Yemen, high plateau, 14-4-82 [14 April 1982], I.L. Hamer (SEMC). This is the exact label data from the holotype male and is unfortunately not very precise but likely refers to the mountainous area north of Sana’a and bordering Jazan, Saudi Arabia.

Paratypes.

1♀, Saudi Arabia, Asir, Abha, Sawdah [Sodah] (near ropeway), 2670 m, 18°17'37.19"N, 42°21'31.49"E, 22-v-2012 [22 May 2012], M.A. Hannan (KSMA); 1♀, Saudi Arabia: Asir, Abha, Sodah, nr. dam, 2500 m, 18°14'11.64"N, 42°24'49.96"E, 22-v-2012 [22 May 2012], M.S. Engel (SEMC); 1♀, Saudi Arabia, Abha, 6.vi.1972 [6 June 1972], 18.13°42.30°E, A.W. Harvey (SEMC).

Diagnosis.

The new species is superficially similar to Thyreus ramosus and Thyreus ramosellus (Cockerell) but can be distinguished most readily in the form of the male terminalia [cf.Figs 5-9 with those in Lieftinck (1968)], particularly in the unique structure of the seventh metasomal sternum and even more extensively with the latter species. In addition, the ventral longitudinal carina of the male metafemur is incomplete (as in Thyreus ramosellus , complete in Thyreus ramosus ) but the apex of the metatibia lacks a comb of dense, long, fine, plumose setae (present in Thyreus ramosellus , absent in Thyreus ramosus ). Females of Thyreus shebicus differ from Thyreus ramosus and Thyreus ramosellus in that plsa (anterior posterolateral mesoscutal) does not meet pls (posterolateral mesoscutal) and is well differentiated from the latter, and pls (posterolateral mesoscutal) is generally smaller in the new species, separated by more than the diameter of an individual pls (posterolateral mesoscutal) [distance equal to or frequently less than the diameter of pls (posterolateral mesoscutal) in Thyreus ramosus and Thyreus ramosellus ]. The new species may be distinguished from the widespread Thyreus histrionicus (Illiger), another superficially similar species, by the more deeply sinuate mesoscutellar posterior margin, the incomplete ventral longitudinal carina of the male metafemur (complete in Thyreus histrionicus ), the outer surface of the metabasitarsus not concave (concave in Thyreus histrionicus ), the presence of spots on the male sixth tergum (absent in Thyreus histrionicus ), and the form of the hidden sterna and genitalia [cf.Figs 5-9 to Lieftinck’s (1968) figure 20].

Description.

♂: Total body length 10.0 mm; forewing length 7.5 mm. Head wider than long (length 2.3 mm, width 2.9 mm); upper interorbital distance 1.8 mm; lower interorbital distance 1.3 mm. Intertegular distance 2.2 mm; mesoscutellar posterior margin with median emargination, weakly sinuate (Fig. 3), apicolateral angle only weakly produced. Ventral longitudinal carina of metafemur incomplete, carinate only in apical two-thirds, basad carina becomes a defined acarinate angled ridge (in this regard somewhat similar to Thyreus ramosellus ); inner anterior angle of metatibia not swollen or projecting into prominence or point between metatibial spurs but inner apical border bearing spurs produced gradually outward and posteriorly bordered by apical depressed area with more elongate black setae; apex of metatibia without comb of dense, long, fine, plumose setae; outer surface of metabasitarsus not concave. Apex of seventh metasomal tergum with apicolateral prominences distinct, acutely pointed, length of individual prominence less than one-half of distance between them, truncate margin between prominences straight, without medial emargination or swelling; male terminalia as in Figs 5-9.

Labrum with coarse punctures separated by less than a puncture width except medially and basally separated by a puncture width or slightly less and small, circular, basolateral impunctate areas, integument between punctures smooth, basomedially with shallow, short V-shaped furrow with smaller closer punctures therein; clypeus with small nearly contiguous punctures, integument between smooth; supraclypeal area as on clypeus except punctures sparse medially; lower face as on clypeus except punctures more well defined, becoming progressively larger toward upper frons; punctures become smaller and sparser in ocellocular area, integument between punctures smooth; punctures weaker and shallower on vertex, separated by less than a puncture width immediately posterior to ocelli and bordering preoccipital carina, otherwise rather sparse on vertex; punctures of gena coarse, shallow, and progressively more dense from above to nearly contiguous by midlength; postgena finely imbricate and impunctate. Pronotum with coarse, shallow punctures separated by a puncture width or less, integument between smooth to faintly imbricate; mesoscutum with well-defined, coarse, contiguous punctures laterally (Fig. 3), punctures slightly more widely spaced medially such that punctures separated by about 0.25-0.5 times a puncture width, integument between punctures smooth; axilla with punctures contiguous; mesoscutellum with punctures as on mesoscutum except separated by 0.25-0.75 times a puncture width, more closely spaced laterally; pleura with coarse, nearly contiguous punctures, integument between punctures (where evident) finely and faintly imbricate, punctures of mesopleuron ventrally becoming more elongate and widely spaced, punctures of preëpisternal area and metapleuron smaller than those of mesopleuron and contiguous; hypoepimeral area large, coarse, nearly contiguous punctures; propodeal lateral and posterior surfaces with coarse, shallow, ill-defined, nearly contiguous punctures. Metasoma with small punctures separated by a puncture width or more often less (Fig. 4), punctures more coarse, larger, and somewhat more poorly defined on discs of more apical terga, integument between faintly and finely imbricate, apical margins narrowly impunctate and finely imbricate; sterna with similar punctation except those on discs of more basal sterna more widely spaced and becoming more poorly defined on more apical sterna.

Integument black except dark brown on labrum, mouthparts, legs, and apically on mesoscutellum, seventh metasomal tergum, and on apical sterna. Wing membranes hyaline and slightly infumate except with whitish along apical border of 2rs-m and 2m-cu (Figs 1-2), veins dark brown to black.

Pubescence generally fuscous to black over entire body except in the presence of long plumose white setae over most of face (Fig. 10), posterior on vertex, ventral margin of mandible, entire gena, postgena, outer surface of protibia and probasitarsus (although white setae appressed and short on this surface), outer surface of mesotibia and mesotarsus (appressed on these surfaces), apical ventro-posterior border of mesofemur, outer posterior angles of meso- and metacoxae, outer surface of metatibia and metarasus (appressed on these surfaces), and on mesosoma (using the annotation system of Lieftinck 1962, 1968) as follows: deps (dorsal mesepisternal) and lpn (lateral pronotal) present; als (anterolateral mesoscutal) present but diffuse and faint; ms (median mesoscutal) present but diffuse and faint; mls (mediolateral mesoscutal) present albeit very diffuse; plsa (anterior posterolateral mesoscutal) present along border with tegula, not meeting pls (posterolateral mesoscutal) posteriorly; t (tegular) present and prominent posteriorly on tegula; pls (posterolateral mesoscutal) present, not extending laterally to meet plsa (anterior posterolateral mesoscutal); ps (parascutellar) and s (mesoscutellar) absent; deps (dorsal mesepisternal), hypm (hypoepimeral area), and lp (lateral propodeal) present, veps (ventral mesepisternal) present albeit diffuse (Figs 1, 3) (much of these white patches are diffuse in the male and partially rubbed off as preserved, most patches more well defined in female). Mesoscutellum with patch of long, plumose, white setae extending posteriorly from undersurface of mesoscutellum medially, patch wide but not reaching to apicolateral corners. Metasomal terga with prominent patches of appressed, plumose white setae as follows: first metasomal tergum with large, L-shaped patches laterally; second metasomal tergum with lateral patch L-shaped although transverse section more well developed; third through sixth metasomal terga with transverse lateral patches, those of sixth tergum more rounded (Fig. 4).

♀: As described for male except in usual gender differences and as follows: Total body length 8.1-9.9 mm; forewing length 7.1-8.1 mm. Head wider than long (length 2.3-2.6 mm, width 2.9-3.4 mm); upper interorbital distance 1.8-1.9 mm; lower in terorbital distance 1.3-1.5 mm. Intertegular distance 2.3-2.7 mm; mesoscutellar posterior margin as in male but sometimes sinuate margin weaker and posterior angles more prominent. Pygidial plate relatively narrow, lateral margins largely straight and converging apically, apex broad and truncate, surface imbricate and impunctate, apically with weak medial carina.

Mesoscutal punctures slightly more spaced than in male; metasomal terga with punctures generally separated by less than a puncture width, apical margins narrowly impunctate and imbricate except apical margin of fifth tergum broadly impunctate and imbricate, covering approximately apical half.

Integument and pubescence as in male except reddish brown on pygidial plate; white mesoscutal setal patches generally more well defined and not as diffuse as in male; second through fifth metasomal terga with transverse lateral patches (Fig. 2).

Etymology.

The specific epithet refers to the ancient kingdom of Sheba, realm of the Queen of Sheba and the people of Tubba’, and likely consanguineous with the Sabaeans who occupied several of those areas in the southwest of the Arabian Peninsula in which the species here has been taken.