Rugosothynnus, Brown, Graham, 2015

Brown, Graham, 2015, Rugosothynnus gen. nov. (Hymenoptera: Tiphiidae: Thynninae: Rhagigasterini), a newly recognised Australian genus, Zootaxa 3925 (3), pp. 361-386 : 362-363

Rugosothynnus gen. nov.

Type species: Rhagigaster corrugatus Turner, 1910 .

Diagnosis. Male. Anterior margin of pronotum with lateral margins produced and appearing spinose (viewed dorsally) ( Fig. 3 ); ocellar triangle with central orange spot; apical margin of T7 produced and rounded medially, apical margin weakly raised, not otherwise raised or modified; S1 medially sagittally raised into small blade-like triangular projection subtended basally by Y-shaped carina ( Figs 47–49 ); S8 with long upwardly curved apical spine with smaller preapical spine on dorsal margin ( Fig. 46 ); metasoma long with segments strongly sclerotised constricted. Female. Head and body deeply punctate, punctures often elongate and longitudinally aligned ( Figs 5–7 , 45 ); frons and vertex without paired punctate depressions or longitudinal sulci; pygidium subtriangular.

Description. Male. Head. Clypeus convex basally, usually flattened apically with medial sagittal or inverted Y-shaped carina, apical margin truncate or emarginate; margins of hypostoma not expanded; maxillary and labial palps unmodified; antennae short, not reaching propodeum, segments 2x longer than wide, apical segments not arcuate; antennal prominence not strongly raised, usually with V-shaped carina; transverse frontal carina present or absent.

Mesosoma . Anterior margin of pronotum carinate, laterally produced; mesopleural groove absent; propodeum almost angulate in profile; 2m-cu received distal to 1r-m on M by distance less than half length of 1r-m.

Metasoma. Long, narrow and cylindrical, segments constricted; T1 angulate (in profile), as long as wide; S1 medially sagittally raised into small blade-like triangular projection subtended basally by Y-shaped carina, usually strongly medially raised, and often sagittally carinate; T7 convex, produced and rounded posteriorly, apical margin weakly raised, otherwise not modified by raised areas or carinae; S8 concave dorsally with strongly developed upwardly curved apical spine with dorsal subapical spine usually well developed, basal angles rounded or absent, not spinose; genitalia with basiparameres (collectively) long dorsomedially with basal margin broadly emarginate and apical margin narrowly but not deeply emarginate; paramere-basiparamere suture distinct; parameres with lobe or projection arising from dorsal margin which together with apical margin forming setose ring when viewed posteriorly; parapenal lobes and digitus absent.

Colour. Head and body black with an orange ocellar macula, legs rarely ferruginous; wings at least weakly infuscate.

Length. 12–23 mm.

Female. Head. subquadrate to slightly wider than long; eyes large, elliptical; clypeus medially raised, sagittally carinate basally, apical margin truncate; mandibles bidentate; maxillary palps 6-segmented; labial palps 4-segmented; frons not reticulate; paired punctate depressions and paired longitudinal sulci absent.

Mesosoma . Pronotum flat, not tuberculate, not sagittally sulcate; dorsal surface of propodeum longer than wide.

Metasoma. T1 not carinate, anteriorly truncate, anterior angles not subtuberculate; T2 not transversely carinate or transversely rugose; T5 and S5 not subtuberculate; pygidium subtriangular, punctate.

Colour. Head orange, brown or black, sometimes with yellow to orange maculae; body brown or black.

Length. 11–17 mm.

Distribution. South-eastern and south-western mainland Australia.

Etymology. The name is derived from the Latin and is a reference to the rugose microsculpture of the female. The gender is masculine.

Remarks. The genus is morphologically similar to Rhagigaster sensu stricto and Curvothynnus. The former is distinguished in the male by T7 variously swollen apicomedially and the genitalia with a digitate process arising on the inner surface of the paramere, and in the female by the presence of longitudinal paired sulci on the frons. In Curvothynnus the anterior margin of the pronotum is curved forward to form a concave anterior surface, but is not laterally produced into spines in the male, and the head of female has paired punctate depressions on the frons.

Females are morphologically similar to those of Curvothynnus which are distinguished by the presence of punctate depressions on vertex. Rugosothynnus females also resemble some Tachynomyia Guérin-Ménéville (tribe Thynnini) in body size, the deeply punctate microsculture and the subtriangular pygidium (T6). However, Tachynomyia (and related genera Deuterothynnus Brown , Heligmothynnus Brown, Tachynoides Kimsey , Tachyphron Brown ) has the mesopleuron vertically carinate with an angulate projection above the mid coxa, and lacks a dorsal surface to this sclerite as found in the Rhagigasterini.

The males of R. confusus sp. nov., R. depressus sp. nov., R. houstoni sp. nov., R. fulvescens sp. nov. and R. brunneus sp. nov. (all from south-western Australia) are very similar and best separated by examining the genitalia. The females are distinguished by those characters given in the key. The sexes of four of these five species (the female of R. depressus sp. nov. being unknown) were associated from pairs collected in copula or by coincident collection data. Those of R. tristis (Smith) by coincident collection data for specimens from Dongarra, Geraldton, Meeka Stn, Torndirrup National Park and Wathing. Those of R. fulvescens sp. nov. by specimens form Pinnaroo, Southern Cross and Wubin. Those of R. confusus sp. nov. by specimens from Carrabin and Moresby Ra. Those of R. brunneus sp. nov. by specimens from McDermid Rock and Noongar and those of R. houstoni sp. nov. by specimens from Yalgoo.

The females of R. clypeatus sp. nov., R. depressus sp. nov., R. neocorrugatus sp. nov. and R. schichai sp. nov. are unknown. Species from south-western Australia tend to be more rugose with S1 sagittally carinate, especially in the males, than those in the south-east. The biology is unknown other than adults are attracted to flowers and most specimens bear pollen.

Figures

FIGURES 1 – 4. Rugosothynnus burnsi, male. 1. habitus; 2. face; 3. head and pronotum, dorsal view; 4. apex of metasoma, dorsal view.

FIGURES 46 – 49. Rugosothynnus spp. 46. R. houstoni sp. nov., apex of metasoma, male, lateral, open with parameres partially exposed; 47 – 48 R. depressus sp. nov., S 1 – 2, male: 47 ventral, 48 lateral; 49. R. tristis, S 1 – 2, male, lateral, scale line = 0.2 mm.

FIGURES 5 – 7. Rugosothynnus confusus, female. 5. habitus, (mounted above male on same pin); 6. mesosoma, dorsal view; 7. head, dorsal view.

FIGURES 44 – 45. Rugosothynnus spp. 44. R. depressus sp. nov., face, male; 45. Ru fulvescens sp. nov., abdomen, female, dorsal.