Ropalidia caesariata Polasek 2025, sp. nov.
Creators: name: Polašek, Ozren
name: Onah, Ikechukwu
name: Kehinde, Tope
name: Rojo, Veronica
name: Noort, Simon Van
name: Carpenter, James M.
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Vespidae
Ropalidia
Ropalidia caesariata

description: Ropalidia caesariata Polašek sp. nov.
urn:lsid:zoobank.org:act: 7FC383BE-EF96-4D7E-84E9-5A5A7AECC3AC
Type specimens. Holotype: Emanguzi, Natal, South Africa, 1♀ (OLM.0822). Paratypes: Cape Vidal, South Africa, 1♀ (MFNB); Beira, Mozambique, 1♂ (SAM. A027740). The total number of examined specimens: 2♀♀, 1♂.
Diagnosis. Large species, with basally ferruginous-brown body colour with thin yellow markings, and very developed inferior propodeal carina. Males have a characteristic shape of clypeus, covered by long and dense silvery pubescence, in combination with bell-shaped T2.
Description. Female. Wing length: 10.6–10.9 mm. Colour. Basal colour ferruginous-brown, with thin yellow markings (Figure 38b, c, Figure 84a, b). Yellow areas include apical line on clypeus, yellow line along inner eye margin, lower half of antennal socket, small antero-basal yellow spot on mandible (Figure 38c), thin line underneath pronotal carina (Figure 84a, b; absent in paratype), thin posterior band on T2 and corresponding two short spots on S2. Wings yellowish, nervature brown, stigma yellowish and semi-transparent, apical spot dark grey-brown (Figure 84b). Antenna ferruginous, infuscated dorsally, orange-yellowish underneath (Figure 38c, Figure 84b).
Head. Clypeus longer than wide, convex, with projecting apex and slightly curved upes (Figure 38c). Clypeus covered by dense, small and poorly defined punctures, which become less defined wide craters apically. Entire clypeus covered by golden pubescence and longer protruding golden-yellowish setae, about twice longer apically than basally. Frons covered by coarser and more defined punctures, which extend further to tempora and gena, where those are retained only close to eye; posterior part of gena and tempora with less defined punctures or impunctate. Gena thicker than eye, lower part of gena is widest (as opposed to other species, which have higher part of gena widest). Occipital carina well developed, very mildly sinuate (Figure 84b). Eye setae sparse and intermediately long (Figure 38c). Ocellar triangle slightly acute forward. Scape about as long as AF1, pedicel longer than wide, AF2 about 1.5 times as long as wide.
Mesosoma. Mesosoma covered by large and shallow, poorly defined punctures, yellowish pubescence and some longer protruding setae. Infero-lateral pronotal angle elongated, very acute. Mesonotum with large and very shallow punctures, both median and parapsidal furrows well developed. Lateral mesopleuron with very large punctures, which can be merged and somewhat irregular. Tegula with very poorly defined punctures (only uneven cuticular surface remains instead puncta), their medial part covered by yellowish setae that almost entirely obscure underlying punctures. Scutellum with flattened surface, coarse and shallow punctures, and well-developed median carina extend almost to its end. Metanotum with very large impunctate triangular area; median tooth not developed (Figure 38a). Metapleuron with very scattered, shallow and poorly defined punctures; central part of metapleuron impunctate. Striations of propodeum regular and strong in lateral surface and excavation, upper carina not developed, but inferior propodeal carina strongly developed, elevated above propodeum surface (Figure 38a).
Metasoma. Metasoma covered by short yellowish setae (Figure 84a, b). T1 pyriform, narrow (Figure 84b). T2 bell-shaped, shorter, with oblique (non-parallel) sides, its surface covered by shallow, small and directional punctures (Figure 38b). T2 lamella brown, opaque, without visible T2/S2 notch (Figure 84b). Lamellar cut-out more or less even, T2 slightly longer than S2.
Males. Wing length: 10.5 mm. Males resemble females in general appearance. Colour. Clypeus, mandibles, anterior part of gena, inner orbit, interantennal area and eye sinuses yellow-whitish; frons brown (Figure 69a). Pronotum with yellow inferior angle, and some suffused yellow areas along mesonotal and mesopleuronl margin. Mesopleuron largely yellow anteriorly, brown laterally. All coxa yellow anteriorly and brown posteriorly, similarly to femur; tibia brown with irregular yellow markings on tibia I. Tarsi darker.
Head. Clypeus longer than wide, with projecting and depressed apex, nearly parallel sides and curved upes; shallow punctures are hardly discernible by long silvery pubescence of equal length basally and apically (Figure 69b). Gena about 0.7 times as wide as eye. Mandible matt, with occasional shallow puncture. Scape slightly thickened (not more than 1.5 times of the AF1 width), pedicel wider than long, AF1 conspicuously longer than scape (about 1.4 times). Tyloids matt, starting on AF1 (visible along its entire length), occupying most of inner surface in more distal segments. Terminal flagellomere very elongated and curved with obtuse tip (Figure 69b).
Mesosoma. Tarsal spur I not developed.
Metasoma. S7 with concave surface.
Male-female pairing strength: Moderate; based on morphological similarity of propodeum, body size and general colour pattern, and distribution pattern.
Distribution. Mozambique, South Africa (Northern Kwazulu-Natal).
Etymology. The name is the Latin adjective caesariatus -a -um, “longhaired”, referring to the hairy male clypeus.
Similar species: R. dondo sp. nov. and R. puncta (FABRICIUS) stat. rev., both of which have less developed inferior propodeal carina. Notably, there might be some difficulties in the separation of oddly coloured R. dondo sp. nov. specimens (without yellow markings), but in these cases, punctures of coxa II and III provide separation features, alongside the shape of T2 (much larger and primarily parallel-sided in R. dondo sp. nov.). Very oddly coloured R. puncta can be separated based on the shape of T2, primarily parallel-sided in R. puncta, more slender T1 (bulkier in R. puncta) and brown coxa pair I (usually entirely yellow in R. puncta). Males are easily separated from all other species by clypeus shape and pubescence and terminal flagellomere shape.
Genetics. A single (holotype) specimen was COI genotyped, suggesting an isolated lineage, with some basal relatedness to R. africana (CAMERON) stat. rev. The only COI cluster belonged to BOLD: ADN 4684.
description: Published as part of Polašek, Ozren, Onah, Ikechukwu, Kehinde, Tope, Rojo, Veronica, Noort, Simon Van & Carpenter, James M., 2025, Revision of the mainland African species of the Old World social wasp genus Ropalidia Guérin-Méneville 1831 (Hymenoptera; Vespidae), pp. 1-142 in Zootaxa 5626 (1) on pages 72-73, DOI: 10.11646/zootaxa.5626.1.1, http://zenodo.org/record/15325272