Euodynerus (Euodynerus) histrionicus ( Gerstäcker, 1857 ), Selis & Carpenter, 2023

Selis, Marco, 2024, Revision of the Afrotropical species of Euodynerus Dalla Torre (Hymenoptera: Vespidae: Eumeninae), Zootaxa 5399 (4), pp. 365-380 : 369-371

Euodynerus (Euodynerus) histrionicus ( Gerstäcker, 1857)

Figs. 2 , 7B

Rhynchium histrionicum Gerstäcker 1857: 463 , ♀ —“Mossambique” (holotype ZMHB).

Rhynchium foraminosum Gribodo 1895: 101 , ♀ —“Lourenso-Marquez” (holotype lost, previously in MSNG).

Diagnosis. Readily distinguished from other African Euodynerus by the following characters: head and mesosoma with sparse short pale setae and pubescence, mandible robust, mesosoma depressed with flattened mesoscutum and scutellum, tegula about 2× as long as wide with long posterior lobe, outer margin weakly curved, T1 with ill-defined translucent margin and nearly impunctate, T2 with punctures becoming progressively coarser apically, pattern red and black without yellow markings, male F11 bacilliform and straight. Genitalia in Fig. 7B .

Material examined. HOLOTYPE OF RHYNCHIUM HISTRIONICUM : “ histrionicum / Gerst. / (caput falsum!) //Type// Mozambique /Tette / Peters S. // 2662” ( ZMHB). ANGOLA: Bruco, 26.II–2.III.1972, 1♁ ( MSNVE); ERITREA: Cheren, 1894, leg. D.F. Derchi, 1♁ ( MSVI); MALAWI: Salima, Grand Beach Hotel , 25.II.1975, leg. G.G.M. Schulthen, 1♀ ( MSNVE); MOZAΜBIQUE: Port. E. Africa, Valley of Kola R., near E Mt. Chiperone , 1500–2000 ft., 6.IV.1913, leg. S.A. Neave, 1♀ ( MSNVE); Zambesi, Caia, 10.XI.1910, leg. H. Swale, 1♀ ( MSNVE); SOUTH AFRICA: Transvaal, Punda Milia, 900 ft., Kruger P., 22.II.1969, leg. R.T. Simon Thomas, 1♁ 1♀ ( MSNVE); Zululand, Mfongosi, IV.1923, leg. Jones, 1♀ ( MSNVE); TANZANIA: SE edge Ruaha N, Mkwawa, 13-17.XII.2014, leg. S. Prepsl, 1♁ 1♀ ( MSVI); ZAΜBIA: N.E. Rhodesia, Mid-Luangwa Valley , 1800 ft., 23–31.VIII.1910, leg. S.A. Neave, 1♀ ( MSNVE).

Distribution. Angola, Botswana, Eritrea *, Eswatini, Malawi, Mozambique, South Africa, Tanzania, Zambia, Zimbabwe ( Bequaert 1918; Carpenter et al. 2009; Gerstäcker 1857, 1862; Gribodo 1895; Radoszkovsky 1881; Selis & Carpenter 2023; von Schulthess 1899, 1922a, 1922b) ( Fig. 8 ).

Notes. Carpenter et al. (2009) reported this species as present in Namibia, citing von Schulthess (1922b) as source of this occurrence. In fact, the cited paper only reports localities in Botswana, Eswatini, Mozambique and South Africa. The species is expected to be found in Namibia too, but we currently do not have any confirmed occurrence from that country.

The male from Cheren ( Eritrea) could represent a different species, being collected very far away from the rest of the distributional area of the species and having some differences in clypeus, F11 and propodeal denticulation. The differences are rather subtle and could be consequences of the reduced size of the specimen, therefore they are tentatively regarded as intraspecific variation; moreover, no differences could be found in the genitalia. More material is needed to ascertain whether the Eastern African population represents a different species or just a local form of Euodynerus histrionicus .

Euodynerus histrionicus and the newly described E. gaya form a rather peculiar group inside of Euodynerus , currently known from sub-Saharan Africa only and well-differentiated from the Palaearctic taxa, including the other species included in the present revision. This group is characterized by more robust mandibles, markedly depressed and relatively elongate mesosoma, translucent margin of T1 not distinct, and F11 of male bacilliform and dorsally depressed. Similar characters are observed in another Afrotropical genus related to Euodynerus , Proepipona Giordani Soika , in which Giordani Soika considered E. histrionicus to belong according to labels pinned under specimens in his collection. However, E. histrionicus and E. gaya show several characters observed in Euodynerus but not in Proepipona : vertex of female without large transverse impunctate area, mesepisternum with strongly developed epicnemial carina, tegula elongate with long posterior lobe and weakly curved outer margin, metanotum markedly angled and with denticulate transverse carina, and propodeum strongly carinate. It is possible that E. histrionicus and E. gaya will prove to not belong to Euodynerus s. str., but a thorough revision and phylogenetic analysis of the genus is needed to ascertain the relationships between Euodynerus , Proepipona and these two aberrant species; for this reason, they are kept in Euodynerus for the time being.

Figures

FIGURE 2. Euodynerus histrionicus (Gerstäcker, 1857). A, habitus in dorsal view, female. B, head in frontal view, male. C, head in frontal view, female. D, flagellum in lateral view, male. E, head in dorsal view, female.

FIGURE 7. Male genitalia: aedeagus in ventral view, aedeagus in lateral view, digitus + volsella. A, Euodynerus gaya Selis, sp. nov. B, Euodynerus histrionicus (Gerstäcker, 1857). C, Euodynerus niloticus (de Saussure, 1855). D, Euodynerus salzi (Giordani Soika, 1952). E, Euodynerus semiaethiopicus (Giordani Soika, 1943).

FIGURE 8. Distribution map of Afrotropical species of Euodynerus Dalla Torre.