Borgatomelissa samailensis Monks and Polaszek, 2024

Monks, Joseph, Polaszek, Andrew & Al-Jahdhami, Ali A., 2024, The bee genus Borgatomelissa Patiny, 2000 (Anthophila: Andrenidae: Panurginae) with the description of a new species from northern Oman, and a key to species, Journal of Natural History 58 (21 - 24), pp. 674-687 : 675-679

Borgatomelissa samailensis Monks and Polaszek sp. n.

( Figures 1–3 )

Diagnosis. A medium-sized species (~ 11 mm) closely resembling B. brevipennis but distinguishable by differences in colour, and by the shape of the subantennal and epistomal sutures (see below). The species is separable from the minute B. flavimaura due to the size as well as the more shaggy, loose hairs on the mesoscutum of the latter species; these are dense and appressed in B. samailensis . Borgatomelissa is separable from other genera in the tribe Melitturgini by the combination of three submarginal cells, stigma almost as long as prestigma, only the first segment of the labial palp being long, and the maxillary palp consisting of six segments ( Michener 2007). The genus is similar to Meliturgula Friese but can be separated by the presence of dense, short appressed hairs on the mesoscutum of Borgatomelissa . While B. flavimaura has long erect hairs scattered amongst the dense, appressed hairs of the mesoscutum, Meliturgula lacks the extremely dense appressed hairs seen on the mesoscutum of Borgatomelissa species. Male Borgatomelissa can be further distinguished from Meliturgula by the very slender, long gonostylus (as long as the gonocoxite), while in the latter, the gonostylus is robust and only half or less as long as the gonocoxite.

Head. Labrum, clypeus, scape, paraocular and supraclypeal areas lemon yellow ( Figure 1 ). Frons and vertex black. Mandibles yellow before merging into brown and then black at apex. Genal area yellow before turning black as genal area meets vertex. Two yellow spots adjacent to outer ocelli. Pedicel and flagella yellow ventrally, red dorsally. Clypeus, paraocular area, frons, and vertex very lightly pilose with white hairs. Fringe of white hairs continues along genal area, becoming longer and more erect along the lower hind margin. Fringe of golden hairs present on the ventral side of the mandibles. Tufts of golden hairs present on labrum. Inner subantennal suture almost straight. Outer subantennal suture curves outwards laterally, joining epistomal suture before it curves down laterally. Upper margin of clypeus almost straight. Face with sparse, shallow punctures. Vertex straight, not raised above lateral ocelli. Clypeus viewed laterally flat. Genal width less than half that of compound eye. Inner margin of eye straight. Ocelloccipital distance less than half the width of the posterior ocelli.

Mesosoma. Pronotum, mesoscutum and mesoscutellum highly punctate with small, distinct, regular punctures. Maximum distance between punctures, width of two punctures. Integument of pronotal lobe, anterior half of tegula, and centre of metanotum yellow. Mid and posterior half of tegula clear. Lateral edges of metanotum black. Yellow posterior band along the margin of the mesocutellum and metanotum ( Figure 2 ). Remainder of the mesosoma with the integument black. Where hair is not abraded, dense appressed white hairs on the mesoscutum, mesoscutellum and metanotum. Sparse, erect hairs projecting through the appressed hairs on the anterior of the mesoscutum. Long, shaggy white hairs stretching around the lateral sides of the mesosoma from the pronotum to the propodeum. Metanotum projecting upwards. Propodeum angulate, with a clear division between the sub-horizontal anterior half and the vertical posterior half ( Figures 2 and 3 ).

Metasoma. T1–3 red-orange with brown markings medially and posterolaterally ( Figure 3 ). T4–6 integument is brown. T1 with sparse, long, appressed white hairs on the anterior surface. T2–5 with white, appressed hairs along the pregradular areas. S1–5 with white apical hair bands. Apical bands of S5 strong. Tergites densely punctated throughout although punctures on T5 larger and slightly sparser (distance between punctures more than 2× the width of a single puncture). Weak apical hair bands across all tergites.

Legs and wings. Legs yellow with a weak, pale scopa present on hind tibia and basitarsus. The mid tibia bears one long, serrated tibial spur, extending the whole length of the mid-trochanter. Mid femur flattened and angular ventrally with a row of golden short bristles proximally. Tarsal claws bifid. Arolium present. Wings with three submarginal cells, second and third submarginal shorter than the first. Wing veins orange except vein R black dorsally.

Molecular results. The CO1 barcode sequence of B. samailensis differs from that of B. brevipennis by 51 substitutions (of a total of 603 bases in both edited sequences). Of these, 17 = A ˃ T; 14 = T ˃ A; 10 = C ˃ T; 4 = T ˃ C; 3 = A ˃ G; 2 = C ˃ A; 1 = A ˃ C. The substitutions are distributed rather evenly along the sequence with no outstanding region of difference.

The raw DNA barcode sequence is available on the BOLD Systems database under BIN URI: BOLD: ACZ0945. The edited CO1 sequence (603 bp) is available on GenBank as a FASTA file under accession number OR038198. Two other specimens of B. samailensis , also collected in Oman (by Jason Gibbs) are currently deposited in the Laurence Packer collection at York University, Toronto, Canada. Their DNA sequences have been confirmed (by Laurence Packer) as identical to ours, but are not yet publicly available.

Notes. The holotype and one paratype were collected from Ochradenus aucheri Boiss ( Resedaceae ) in a low wadi (dry riverbed).

Etymology. The species is named after the town of Samail, adjacent to the type locality. The town lends its name to the wadi separating the Eastern and Western Hajar Mountain ranges, known as the Samail Gap.

Material examined. Holotype female. OMAN: Ad-Dakhiliyah Region, nr. Samail , 23.267N, 57.984E, 420 m, 16 April 2016, on Ochradenus aucheri J. Monks leg. ( NHMUK 010819621 ) . Paratype female: Data as for holotype ( NHMUK 015663931); Paratype female: OMAN: Samed Ashan , 22.823°N, 58.150°E, 22 March 2019, Ali Al Jahdhami leg . ( NHMO).

Figures

Figure 1. Head of Borgatomelissa samailensis Monks and Polaszek sp. n., with lemon yellow integument and straight inner subantennal suture.

Figure 2. Yellow posterior band along the margin of the mesocutellum and metanotum of B. samailensis Monks and Polaszek sp. n.

Figure 3. T1–3 of B. samailensis Monks and Polaszek sp. n., red-orange with brown marking medially and posterolaterally.