Ropalidia acuminata 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 acuminata

description: Ropalidia acuminata Polašek sp. nov.
urn:lsid:zoobank.org:act: 207A6FE8-7C9C-4A8E-9ECE-40D615B0A018
Type specimens. Holotype: Chingola, 25 km W, Zambia, 1♀ (OLM.0272). Paratypes: Kikwit, DR Congo, 2♀♀ (RMCA); Kamina, DR Congo, 9♀♀ (RMCA); Kapona, 27 mi S, DR Congo, 5♀♀ (CAS); NW Tanzania, Tanzania, 3♀♀ (NMW); Sumbawanga, Ufipa, Tanzania, 1♀ (MSNV); Sumbawanga, 32 mi SE, Tanzania, 1♀ (CAS); Kapiri, Zambia, 1♀ (RMCA); Kasempa, 27 km N, Zambia, 2♀♀ (OLM); Chisasa, Zambia, 2♀♀ (OLM); Kapiri Mposhi, 100 km N, Zambia, 1♀ (OLM); Chingola, 25 km W, Zambia, 1♀ (OLM); Mutumbwe, Zambia, 1♀ (OLM); Abercorn (Mbala), Zambia, 2♀♀ (NHM); Abercorn (Mbala), Zambia, 1♀ (MSNV). The total number of examined specimens: 33♀♀.
Diagnosis.A larger member of the capensis- group, characterized by a black and brown-reddish body colouration, transparent wings and yellowish stigma, very deep juxtamandibular excavations, projecting and convex clypeus, and large and shallow clypeus punctures in females.
Description. Females. Wing length 6.2–7.8 mm. Colour. Basal colour dark reddish and black (Figure 3b). Clypeus variably coloured; yellow with trident-shaped brown basal spot, larger brown spot, entirely brown or even entirely black (Figure 2a). Frons basally black, with reddish lines along inner orbit extending to vertex. Gena and tempora reddish, area under occipital carina black (Figure 3a). Mandible variably coloured, ranging from yellow with brown basal spot, reddish spot, to completely brown. Posterior surface of head black. Pronotum reddish (varying from lightly reddish to dark reddish with posterodorsal black area), propleuron black, mesopleuron black or black with central elongated reddish area, scutellum and metanotum reddish, mesonotum, metapleuron and propodeum black (Figure 3b). T1 and S1 basally black, sometimes with brownish or reddish posterior area. T2 dark-brown or black, sometimes with dark-red posterior band (Figure 3b). Coxa and proximal half of femur black, distal part of femur and entire tibia reddish-ferruginous; coxa I and/or II can have medially located smaller yellow markings. Tarsus dark-brown or black, sometimes terminal segment slightly lighter (Figure 3b). Scape and pedicel ferruginous, AF1 ferruginous or distally black from above, remaining flagellomeres black dorsally; distal segments sometimes orange underneath. Wings lightly yellowish, nervature light brown, apical spot barely visible, stigma brownish-yellow and semi-transparent (Figure 3b).
Head. Clypeus with strongly convex centre, prominent apex and deep juxtamandibular excavations (Figure 2a). Clypeus about as long as wide. Upes straight, forming strong oculo-clypeal angle. Clypeus base and centre coarsely and shallowly punctate; entire clypeal surface covered by golden or silvery setae, longer apically. Inner orbit depressed, especially behind and lateral to antennal socket; few punctures can be present in this area, but there is always impunctate zone adjacent to inner eye margin (Figure 3a). Head frontally triangular (in contrast to a more rounded head with wider frons in R. ophuzi sp. nov.; Figure 2a, b). Gena thinner, not wider than eye (Figure 3a). Frons coarsely and distinctively punctate, punctures less than diameter apart, covered by whitish setae with forwardly bent tips of nearly equal length as forward ocellus width. Gena strongly punctate, with sparse and defined punctures in posterior third (as opposed to R. ophuzi sp. nov., which has shiny and impunctate posterior area close to occipital carina; Figure 3a, 3 aa). Occipital carina slightly sinuate. Ocellar triangle with substantially wider base. Eyes covered by very short setae or asetose. Scape longer than AF1 (about as long as pedicel+AF1); pedicel about 1.5 times as long as wide, AF2 slightly longer than wide (1.0–1.3).
Mesosoma. Mesosoma covered by shorter yellowish pubescence that turns to longer setae at posterior part of propodeum; entire mesosoma coarsely and densely punctate, especially pronotum and mesopleuron (Figure 3b). Tegula laterally punctate. Mesonotum deeply and densely punctate. Scutellum with coarser punctures than mesonotum, metanotum with similar punctures in proximal half and shiny posterior impunctate area. Metapleuron with retained punctures near anterior margin, impunctate centre and coarser punctures towards propodeum. Propodeal excavation rounded, narrower than metanotum width, covered by fine striae and occasional puncture. Lateral propodeal area strongly striated, superior carina weak, inferior propodeal carina elevated without hyaline rim.
Metasoma. T1 dorsally triangular, rounded posteriorly and sparsely punctate. T2 elongated, with long parallel contour and minimal narrowing towards lamella. T2/S2 suture strongly developed, commonly visible along entire segment length. T2 lamella variable in colour, commonly semi-transparent; lamellar notch visible and obtuse. T2 covered by shallow directional punctures, which turns to superficial punctures dorsally; T2 longer than S2, yielding oblique segment contour. T2 covered by short yellowish setae, those on S2 longer, finer and whitish.
Male. Unknown.
Distribution. Zambia, DR Congo, SW Tanzania.
Etymology. The name comes from the Latin adjective acuminatus, meaning “sharp, acute, pointed”, and refers to the very sharply pointed female clypeus of this species.
Nest. One nest was examined in the early stage of the colony cycle (without meconium openings at the cell bottoms). The nest has a discoid shape with 12 cells. Cell walls are bicolorous, made of dense material. The pedicel is located on the primary cell and rests on the top of the nest. The nest is located on a twig.
Similar species. This species is similar to R. ophuzi sp. nov., separated by gena punctures and colour pattern. The general appearance of females may sometimes resemble R. nigrocerasina sp. nov., which can easily be separated by the shape of clypeus.
Genetics. A single specimen was successfully genotyped (BOLD: ADN 9351), suggesting a basal position within the capensis -group. The sister BIN belongs to R. ophuzi sp. nov. (BOLD:ADO0894), and these two species form a cluster that is sister to all other members of the capensis -group.
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 58-59, DOI: 10.11646/zootaxa.5626.1.1, http://zenodo.org/record/15325272