Hedychrum harteni Rosa, 2024

Rosa, Paolo, 2024, Contributions to the cuckoo wasp fauna (Hymenoptera: Chrysididae) of Yemen with description of five new species and updated checklist, Journal of Insect Biodiversity and Systematics 10 (4), pp. 995-1031 : 1003-1005

Hedychrum harteni Rosa , sp. nov. ( Fig. 5A–F)

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Material examined. Holotype ♀, Yemen: Al-Lahima , 16.X.-31.XII.2000, Malaise trap, leg. A.v.Harten & A.M. Hager ( RMNH) ; Paratypes 2♀♀, same data and collectors of the holotype ( RMNH) .

Diagnosis. Hedychrum harteni sp. nov. may initially resemble a species related to H. rutilans Dahlbom, 1854 due to its elongate pronotum (longer than the combined mesonotum and metanotum) and the coloration of the mesosoma, with a light green pronotum and mesonotum contrasting with a blue metanotum and propodeum. However, the shape of the apical margin of the female third sternum ( Fig. 4F) is typical of species closely related to H. alfierii Trautmann, 1926 . Hedychrum harteni sp. nov. shares several characteristics with H. alfierii ( Fig. 4), which ranges from Egypt to Palestine and Arabia . These shared features include its small size, 5 mm, the apical margin of the female third sternum, which is apically digitate on each hemisternum and medially sinuate along the midline, and the discoloured legs and sterna ( Fig. 4A). However, H. harteni sp. nov. can be distinguished from H. alfierii by the following traits: an elongate pronotum (slightly longer than the scutellum in H. alfierii ); dense, small punctures on the pronotum without polished interspaces ( Fig. 5C) (round and separated punctures on mesosoma, with polished interspaces in H. alfierii , Fig. 4C); first tergum densely punctate basally ( Fig. 5D) (largely polished in H. alfierii , Fig. 4E); metallic blue outer tibiae (non-metallic yellow with a weak rose hue in H. alfierii , Fig. 4A); and contrasting green and blue coloration on the mesosoma (head and mesosoma unicolored green in H. alfierii , Figs 4A, 5C).

Description. Holotype ♀ ( Fig. 5A–F). Body length 5.0 mm.

Head. Vertex, frons and temples densely punctate, with small (0.3–0.4 × MOD) subcontiguous punctures; without polish spaces; large impunctate area (1 × MOD) laterad posterior ocelli; scapal basin deep, with sharp wrinkles; clypeus medially impunctate to slightly wrinkled, laterally with dense, rugose sculpture and undefined punctures; subantennal distance short (0.5 × MOD); clypeal margin with median dark brown thickened apex, laterally with expanded hyaline rim; OOL = 2.4 × MOD; POL = 2.2 × MOD; MW = 0.7 MOD; relative length of P:F1:F2:F3 = 1.0:1.2:0.9:0.8.

Mesosoma. Pronotum elongate, as long as scutellum and metanotum together ( Fig. 5A); pronotal anteromedian line shallow; punctation even, deep, subcontiguous, with small punctures (0.3–0.4 × MOD) ( Fig. 5B); median area of mesoscutum with similar punctures but with larger, polished interspaces, becoming narrower on lateral sides of mesoscutum; notauli as fine lines, barely visible between punctures, parapsidal furrow deeper, more visible than notauli and elongate; mesoscutellum with smaller and sparser puncture, with polished interspaces; punctures on scutellum larger and subcontinuous laterally and posteriorly; metanotum with large, foveate-reticulate punctures, as large as 1 × MOD; mesopleuron with large, polygonal punctures, subcontinuous without polished interspaces. Propodeal projection as acute triangle, pointing outwards; tarsal claws with pointed submedian tooth.

Metasoma. Metasomal first tergum with relatively small punctures dorsally, becoming larger and deeper at sides; punctures smaller and dense basally on second tergum, becoming very sparse on second half of segment, with polished interspaces up to 2–3 puncture diameter ( Figs 5D, 5E); on third tergum with spaced and relatively shallow puncture; third tergum regularly slightly bulging before the apical margin; margin with narrow hyaline rim and two lateral evident angles. Second sternum densely punctate at sides and sparsely punctate medially; third sternum densely micropunctate, with scattered large punctures; apical margin of the third sternum digitate on each hemisternum, sinuate along the midline before the apical teeth ( Fig. 5F).

Colour. Head and mesosoma blue, with a light green hue on pronotum and mesonotum contrasting with blue metanotum and propodeum; metasomal sterna brown without metallic reflections; scape iridescent, pedicel and flagellomeres brown; tegula brown; legs brown on ventral side, with metallic colour on outer side; tarsi brownish to light brown; wings brownish.

Vestiture. Head and mesosoma with short (0.5 × MOD), appressed and whitish setae, longer on propodeum laterally, 1.0 × MOD. Scattered longer setae on mid and hind femora (1.0-3.0 × MOD) ( Fig. 5B) and scattered, erect setae on mid and hind tibiae; thick and longer setae on first and second terga laterally and on the third posterolaterally (1.0 × MOD).

Male. Unknown.

Etymology. The specific epithet harteni is dedicated to Antonius van Harten, who has made significant contributions to the collection of the material examined in this study and to the broader knowledge of the entomological fauna of the Arabian Peninsula over the past three decades.

Remarks. The previous identifications of Hedychrum alfierii in Palestine and Arabia need to be reassessed due to existing uncertainties regarding this species ( types examined, Fig. 4), for example Kimsey & Bohart (1991) classified this species in the genus Hedychridium Abeille de Perrin, 1878 .

Distribution. Yemen (Al-Lahima).