Crossocerus (Oxycrabro) arabicus Gadallah & Edmardash 2024, spec. nov.
Creators: name: Gadallah, Neveen S.
name: Edmardash, Yusuf A.
name: Abu El-Ghiet, Usama M.
name: Al-Fifi, Zarrag I. A.
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Crabronidae
Crossocerus
Crossocerus arabicus

description: Crossocerus (Oxycrabro) arabicus Gadallah & Edmardash, spec. nov.
urn:lsid:zoobank.org:act: DFF00210-C355-4D26-BCEC-ACCB68C7CDC2
Figs 6 (A–D), 7(A–D)
Type material: Saudi Arabia, Holotype (♀), Fifa Mountain (Development Authority Farm-almukhafih), 1260 m [17º16’07ʺN 43º07’32.3ʺE], July, 2023, Malaise trap in coffee orchard, Usama Abu El-Ghiet collector; Saudi Arabia, Paratype (♀), same data, but May, 2023.
Diagnosis. The new species belongs to the subgenus Oxycrabro Leclercq, 1961 based on the following combination of characters: occipital carina complete, not interrupted ventrally (Figs 6B, 7D); mandible bifid (Fig. 6C); collar with a small notch medially (Figs 6B, 7D); mesopleuron with small denticle in front of midcoxa; pygidial plate slightly depressed on apical half (Fig. 7B); body small-sized (4.5–4.8 mm) (Leclercq 1961, 2009: 158, couplet 1).
The subgenus Oxycrabro includes three currently known species (Bohart & Menke 1976; Leclercq 2009; Pulawski 2023): C. (O.) acanthophorus (Kohl) (western and central Palearctic), C. (O.) federationis Leclercq (Malaysia), and C. (O.) taru de Beaumont (Turkey). Our specimens do not agree with any of the three species. They differ from C. taru in having the free margin of the middle clypeal lobe with three distinct minute, rounded teeth (Fig. 6D) (in C. taru the median lobe of the clypeus is slightly concave, see de Beaumont 1967: 353, fig. 71); F1 is 2.0× as long as wide (in C. taru, F1 is 1.3× as long as wide); gaster sculpture differs in both species. C. arabicus differs from C. acanthophorus in having the gastral T 2 and T 3 without basal depressions (in C. acanthophorus both terga are conspicuously depressed basally); flagellomeres distinctly longer than wide (in C. acanthophorus flagellomeres are not longer than wide); although the colour varies in C. acanthophorus, but distribution of yellow maculae differs in both species. The new species differs from C. federationis in the following: propodeum smooth and shiny, with broad median transversely ridged sulcus, lateral surface finely wrinkled (Fig. 7D) (in C. federationis the propodeum is very finely punctate); the free margin of middle clypeal lobe has three distinct minute, rounded teeth (Fig. 6D) (in C. federationis the middle lobe of the clypeus is truncate, without any trace of teeth); median sulcus attaining the middle ocellus not deep (in C. federationis this sulcus is very deep); scutum densely finely punctate throughout, not foveolate at apex (Fig. 7D) (in C. federationis, the scutum is foveolate at apex).
Description of female holotype.
Body length: 4.5 mm.
Colouration (Figs 6A–C, 7C, D). Body black, with the following parts citrus yellow: scape, pedicel beneath, mandible (except black to dark ferruginous tip), pronotum, scutellum, pronotal lobe. Legs: fore and midfemora yellow at apical half and apical two-thirds, respectively; fore and midtibiae entirely yellow, hindtibia yellowish posteriorly, black along most of inner surface; tarsi yellowish white, with somewhat darker apical tarsomeres; tegula golden yellow basally, remainder black, with yellow apex. Wings hyaline (Fig. 7A), with some coloured reflections; veins and pterostigma dark brown.
Head (Figs 6A–D, 7D). In dorsal view as wide as thorax, densely finely punctate; scapal basin smooth and shiny; median sulcus present just above scapal basin, attaining middle ocellus; gena half as long as eye height; occipital carina complete, sharp; eye inner margins conspicuously divergent above, distance separating eyes at the base of clypeus equal to half length of scape, with facets noticeably larger in front than on side; distance between hind ocellus and eye margin greater than 1.5× ocellar diameter; OOL slightly shorter than POL; fine silvery pubescence along lateral edges of scapal basin; scape distinctly long, exceeding scapal basin, inserted just above clypeus; F1 2.0× as long as wide, about as long as F2; clypeus distinctly broad, densely covered with silvery pubescence hiding most of its surface except apex which is smooth and shiny, middle lobe with three distinct minute, rounded teeth apically; gena clothed with silvery pubescence at lower half; mandible bifid, with two equal apical teeth.
Thorax (Figs 6A, B, 7C, D). Pronotum smooth, with minute median notch posteriorly; scutum densely finely punctate throughout; scutellum and metanotum shiny, with dense fine superficial punctures, sparser than on scutum; propodeum smooth and shiny, with broad median transversely ridged sulcus, lateral surface finely wrinkled; mesopleuron densely finely punctate as scutum, with median transverse crenulate sulcus dividing it, with small denticle in front of midcoxa; metapleuron smooth and shiny. Fore wing (Fig. 7A) with marginal cell distinctly truncate apically; recurrent vein received near to midlength of submarginal cell. Legs normal, hindtibia not serrated along its dorsal surface.
Gaster (Figs 6A, B, 7B). Gastral T 1 narrow basally and widened apically, not swollen at apex, slightly longer than T 2 which is broadened at base, wider apically than basally; pygidial plate triangular, with distinctly depressed apical half, alutaceous at base, remaining surface shiny, sparsely coarsely punctate, with sharp edges laterally; gaster sparsely pubescent, distinctly denser on T 5, sterna with dense pubescence.
Distribution: Saudi Arabia (Jazan Province).
Etymology. The name of the new species is based on the country and region of its collection: Saudi Arabia (Arabian Peninsula).
Variations: The only paratype female differs from the holotype in the body length (4.8 mm), and the pale markings being pale yellow to golden yellow rather than bright yellow as in the female holotype.
description: Published as part of Gadallah, Neveen S., Edmardash, Yusuf A., Abu El-Ghiet, Usama M. & Al-Fifi, Zarrag I. A., 2024, New additions to the crabronid fauna of the Arabian Peninsula and Saudi Arabia (Hymenoptera: Apoidea (Spheciformes): Crabronidae), new distribution records and new species, pp. 549-570 in Zootaxa 5403 (5) on pages 557-560, DOI: 10.11646/zootaxa.5403.5.3, http://zenodo.org/record/10562389