Ropalidia irrequieta ( KOHL 1906 )

Ropalidia irrequieta ( KOHL 1906) View in CoL

Icaria irrequieta KOHL 1906

Type material. The species description is based on a single female from Ras Faltak, nowadays Yemen, deposited in NMW. The description fits the examined specimen well, including lacking a fore wing apical spot ( Kohl, 1906) .

Comments. This species is characterized by numerous yellow markings on the body (most notably on the pronotum; Figure 29 View FIGURE 29 aa), lacking an apical spot of the fore wing, impunctate inner orbit in females and rather specific morphology in males.

This species shows an interesting skipping variability pattern, across three geographical regions where it occurs, namely (a) Yemen, (b) Oman and (c) mainland Africa ( Eritrea, Djibouti, Somalia, Sudan). Specimens from Yemen are most melanic, with a reduced amount of yellow colour on the body (with just a thin apical line or in some specimens, almost entirely brown clypeus; Figure 37c View FIGURE 37 ). The same cluster is also characterized by the brown mesopleua, rarely with a smaller yellow spot. Specimens from the second cluster, from Oman, have more yellow colour on clypeus, inner orbit and mandible. This cluster frequently has a bilateral yellow spot on propodeum, yellow markings on coxa I, while remaining coxa pairs remain without those. The third cluster originates from mainland Africa, and it is characterized by the small yellow spot on mesopleuron, obligatory entirely yellow coxa I, postero-lateral yellow quadrant on coxa II (sometimes merged with the basal yellow spot, almost entirely occupying the coxa surface), thick band on T1, T2 and suffused yellow markings on the remaining terga. Also, this cluster often has more yellow on clypeus, most commonly with just a basally attached brown spot ( Figure 37b View FIGURE 37 ), which is almost completely gone in some specimens, yielding nearly entirely yellow clypeus.

Some separation problems may arise in the mainland African species, namely R. guttatipennis (DE SAUSSURE) , while specimens from the Arabian Peninsula are easily separated from the only other known Ropalidia species that occurs there, R. aethiopica (DU BUYSSON) . Notably, reports of R. cincta (LEPELETIER) from Djibouti, neighbouring countries and Yemen ( Madl, 2018) are probably a misclassification, as already pointed out (James M. Carpenter & Gadallah, 2020), and these records are very likely R. irrequieta (KOHL) .

Males are described here for the first time.

Material examined. Assab , Eritrea, 6♂♂ ( HNHM); Gibdo, Djibouti, 2♂♂ ( HNHM); Taiz, Yemen, 1♂ ( HNHM); Wabi Zaid, Yemen, 1♂ ( HNHM); The total number of examined specimens: 10♂♂ .

Diagnosis. This species is characterized by numerous yellow markings on basally brown body, unicolorous terminal flagellomere and the lack of apical spot of the fore wing.

Description. Wing length 7.7–9.1 mm. Colour. African mainland colour pattern ( Figure 95a View FIGURE 95 ). Basal colour light brown, with yellow-whitish markings on clypeus, mandible, most of face (except frons), elongated yellow line on gena. Frons brown, area around ocelli black. Pronotum with thick yellow area, anterior surface of mesopleuron (commonly without lateral spot high on mesopleuron), all coxa pairs and all femora with yellow markings. Mesonotum, lateral surface of propodeum and sometimes even lateral surface of mesopleuron darker brown. Tarsi light brown. Antenna ferruginous from above, yellow-whitish underneath ( Figure 95a View FIGURE 95 ). Arabian Peninsula colour pattern ( Figure 95b View FIGURE 95 ): Basal colour brown, with yellow areas: clypeus (sometimes with faintly brownish spot centrally), mandible (except triangular brown basal area), interantennal area and inner orbit, minute spot on gena, thickened area on pronotum and commonly spot on mesopleuron. Frons and vertex uniformly brown. Anterior surface of mesopleuron entirely yellow, coxa pairs I and II (sometimes and III) with yellow markings, femur I and II (sometimes and III) with yellow patches anteriorly. Tarsi ferruginous or lightly brown. Antenna ferruginous from above, just slightly less dark underneath.

Head. Clypeus slightly wider than long or equally long as wide; upes curved, apex strongly projecting and acute ( Figure 73a View FIGURE 73 ). Clypeus surface weakly convex, with shallow and poorly developed punctures, obscured by very fine silvery pubescence. Inner orbit can have few poorly defined puncta, commonly impunctate. Gena covered by large and shallow punctures; gena 0.8–1.0 times as wide as eye. Ocellar triangle acute forward. Eye setae very short and sparse in Arabian Peninsula, more abundant and longer in mainland African population. Scape shorter than AF1, AF2 1.2–1.4 times as long as wide ( Figure 2b View FIGURE 2 ). Tyloids orange, shiny, originate as AF1 as thin line, become wider at AF4, and occupy more than half of inner surface of segment AF7–AF11. Terminal flagellomere curved and acute ( Figure 47 View FIGURE 47 aa; somewhat shorter in mainland Africa population).

Mesosoma. Mesosoma with large, shallow and dense punctures, especially mesonotum ( Figure 37a View FIGURE 37 ); metapleuron with smaller and sparse punctures. Scutellum with long and developed median carina, metanotum with or without median tooth. Propodeum wide, especially lateral surface, with moderately developed upper carina, shallow excavation and moderately developed striae; inferior propodeal carina not developed at all. Tarsal I spur absent.

Metasoma. T1 rounded and broad in Arabian Peninsula, narrower in mainland Africa; in all cases, T1 has comparatively shorter stem than other African Ropalidia . S7 flattened or mildly concave.

Male-female pairing strength: high; more than half of all examined males originate from nest series with confirmed females.

Distribution. Most of the 204 examined specimens originated from several nest series from Eritrea (62%), followed by specimens from Djibouti (28%), while the remaining specimens originated from Oman, Yemen, Sudan and Somalia. The distribution pattern seems to include Arabian Peninsula and neighbouring mainland African region, where it seems to be allopatric to R. guttatipennis (DE SAUSSURE) .

Genetics. After numerous attempts, three specimens were successfully genotyped for the COI gene, suggesting a basal lineage close to the R. puncta-aethiopica complex and R. nigrofemorata (CAMERON) . All three specimens belong to the identical BIN ( BOLD: ADR5497 ) .