Ropalidia unidentata GORDANI SOIKA 1981

Ropalidia unidentata GORDANI SOIKA 1981 View in CoL

Ropalidia unidentata GIORDANI SOIKA 1981 View in CoL

Type material. Giordani Soika described this species based on a holotype, two paratype females from ZSM and an additional paratype female from HNHM ( Giordani Soika, 1981). All of the type specimens were examined, and all fit the species description well. Males are described here for the first time .

Comments. A very similar species to R. nobilis (GERSTAECKER) , with dark-reddish basal colour and a specific pattern of contrasting yellow spots. The pattern includes two spots on the pronotum, a quadratic area lateral to parapsidal furrows on the mesonotum, and frequently two smaller spots on the propodeum. Besides the colour pattern, this species also has a longer pubescence than R. nobilis (GERSTAECKER) , providing a morphologic separation feature for specimens with an unusual colour pattern (such specimens were more common in Malawi and Zimbabwe). Similarly to R. nobilis (GERSTAECKER) , this species also has a colour pattern cline; specimens from the Northern distribution range ( Kenya, Tanzania) have strong yellow spots, while further towards South spots become marginally reddened, all the way to almost entirely reddish in some specimens from South Africa. Males are described here for the first time.

Males.

Material examined. D.O. Afrika [= Tanzania], 1♂ ( MFNB.11). The total number of examined specimens: 1♂ .

Diagnosis. Similarly to females, males have highly characteristic colour pattern, which is sufficient for species determination. Some problems might arise in separating oddly coloured specimens of R. nobilis (GERSTAECKER) , but in these cases, the shape of terminal flagellomere and pubescence can provide sufficient determination features.

Description. Males. Wing length 8.1 mm. Colour. Basal colour lightly brown-reddish (less reddish tone than examined females). Clypeus yellow, with large brown basal ( Figure 66a View FIGURE 66 ). Mandible brownish with antero-basal yellow spot; gena without yellow markings. Pronotum with bilateral yellow spot, area lateral to parapsidal furrows yellow, tegulae mostly yellow (only anterior third of tegulae surface lightly brown). Anterior surface of mesopleuron with large patch, coxa I and II yellow, coxa III with suffused yellow patch. Femur brown, distal surface of femur I and II with suffused yellow patches, all tibia lightly ferruginous, tarsi equally coloured to tibia. T1 with two large bilateral spots that are not merged medially, rest of metasoma brownish.

Head. Clypeus flattened, apex only slightly protruding, not depressed and apically obtuse ( Figure 66a View FIGURE 66 ). Upes moderately curved, OCA not developed. Clypeus very shallowly punctate basally, entire surface with short silvery pubescence. Gena thin, about half of eye width, shallowly and sparsely punctate. Frons with dense, large and moderately deep punctures and longer silvery setae; similar features present on tempora and gena, with shorter protruding setae. Eyes covered by sparse setae of intermediate length (in contrast to females, which have asetose eyes). Scape slightly thickened, about 1.3 times as thick as AF1 base, pedicel about as long as wide, AF1 longer than scape, AF2 about 1.7 times as long as wide. Tyloids flat and not shiny, originate on AF1. The terminal flagellomere elongated, tip almost reaches 90° in relation to base. Tyloids are flat and matt. Terminal flagellomere elongated, equally curved, with obtuse tip ( Figure 66b View FIGURE 66 ).

Mesosoma. Pronotum and mesonotum with large, defined and shallow punctures. Both head and mesosoma covered by white pubescence and equally coloured, longer white setae with bent tips.

Metasoma. T1 strongly widened, much more than any of examined females of this species. T2 short, with intermediate-sized directional punctures and some protruding white setae. S2 with longer protruding setae. T2/S2 suture poorly visible, no T2 lamella notch; lamella yellow, opaque. Terminal sternum weakly concave.

Male-female pairing strength: high; based on overall appearance, similar pattern of yellow spots on body, distribution similarity and differences from R. nobilis (GERSTAECKER) males. Genotyping was not attempted due to old age of the specimen.

Distribution. Most specimens originated from Tanzania (49%), Mozambique (14%), Zimbabwe (12%), Malawi (8%) and Zambia (6%), while the remaining specimens originated from Kenya and the South Africa.

Colour pattern. Both R. nobilis (GERSTAECKER) and R. unidentata GIORDANI SOIKA have a general overall resemblance, which is not shared by the genetically closely related R. fita sp. nov. and R. amanhii sp. nov. Furthermore, R. nobilis (GERSTAECKER) and R. unidentata GIORDANI SOIKA seem to share a distribution pattern to a great deal, with the only exception being that R. unidentata GIORDANI SOIKA was not seen from Uganda and DR Congo. In addition, these two species seem to resemble the overall colour pattern of Polistes defectivus GERSTAECKER , (= Polistes waldoi DOVER ), confirming previously implied Ropalidia - Polistes co-evolution through Mullerian mimicry (Supplementary Figure 20 View FIGURE 20 , 21) ( Bequaret, 1918; Giordani Soika, 1981). This is further supported by the Polistes defectivus GERSTAECKER distribution areal, which spans two more countries besides these where the two Ropalidia species were reported from ( Bequaret, 1918; J. M. Carpenter, 1996).

Nest. A single nest was observed on iNat. The nest had an elongated shape, at least 25 cells long and up to three full-length cells wide, with an incomplete length of the accessory cells on the sides. Interestingly, even these lateral incomplete length cells had larvae in them. The cell wall is lightly brown, with an occasional layer of an orange or brownish colour. Opercula are lightly brownish, with occasional orange nodules. The nest was built on wooden planks. Colony size appeared small, with just two visible adult females on the nest (iNat:10894712). A hive chafer raided the observed nest, most likely Oplostomus fuligineus OLIVIER.

Genetics. Two specimens were successfully genotyped for the COI gene, one from Malawi and the other from the island of Pemba in Tanzania, and both belonged to a single cluster (BOLD:ADM2244), suggesting genetic homogeneity of these populations. Based on the COI gene, this species is a member of the nobilis -group, with the least distance to R. fita sp. nov.