Pirhosigma transfluvium Ferreira & Oliveira, 2017

Ferreira, Wellington D., De Oliveira, Letícia A., Inez, Tiago G. & Hermes, Marcel G., 2017, A new species of Pirhosigma Giordani Soika, 1978 (Hymenoptera, Vespidae: Eumeninae), with additional notes and a key to the species in the genus, Zootaxa 4300 (2), pp. 269-278 : 270

Pirhosigma transfluvium Ferreira & Oliveira , new species

( Figs. 1–6 )

Comments and diagnosis. Pirhosigma transfluvium has a preapical fossa on T1 and lacks a pretegular carina, both typical of Pirhosigma , and shares with most of the species, except for P. superficiale ( Fox, 1899) , the conformation of the last flagellomere of the male antenna: small, triangular, and folded over F9 ( Fig. 3 ). The species is similar to P. limpidum , with T1 more robust (compare Figs. 4–5 and 10 ) and T2 longer than wide (compare Figs. 6 and 11 ), but the male antenna is quite different, with evident large tyloids in P. transfluvium ( Fig. 3 ) and tiny and tubercular tyloids in P. limpidum ( Fig. 9 ). P. transfluvium differs from other species of Pirhosigma by the following set of features: distance between lateral margins of clypeus short ( Fig. 2 ); T2 with evident and deep punctures ( Figs. 5–6 ) and S2 without abrupt basal elevation ( Fig. 5 ).

Description. Holotype male.

Color. Integument predominantly yellow. Brownish marks in the following regions: broad spot on the vertex surrounding the ocelli; median longitudinal band in the mesoscutum, connecting a basal and an apical spot; short spot on the lower surface of the metanotum; mark on the anterior surface of the mesepisternum and on the lateral upper surface extending to the lower side of the propodeum; a darker band surrounding the longitudinal groove of the propodeum; dark spot at the base of T1; T2 and S2 with black and brown marks quite evident. T3–7 and S3–7 brownish with straw-yellow apex. Antennae orange, gradually darker on apical antennomeres. Yellow legs with brown spots. Brown hyaline wings.

Pilosity. Whitish pubescence on all body surface. More elongated and abundant setae in T1–7 and S1–7. Shorter setae on the surface of the clypeus, legs and base of the antennae.

Sculpture. Clypeus mostly smooth with shallow punctures not evident; frons and vertex with coarse and deep punctation, distance between punctures smaller than its diameter. Pronotum with wrinkled appearance, with dense punctation; mesepisternum with dense and coarse punctation in its upper portion, anteriorly with more sparse punctures; mesoscutum and scutellum with coarse punctation; metanotum with shallower and less evident punctures. Propodeum with coarse punctation with punctures of greater diameter in the region of the longitudinal groove. T1 with evident punctures apically; T2 with deep and distinguishable punctation.

Structure. Labrum rounded, narrow. Clypeus longer than wide; distance between lateral margins of the clypeus short; clypeus’ apex narrow and emarginate, with well-developed lamella; short and not carinate teeth present. Inter-antennal region without cariniform elevation. Pronotal carina developed in all its extension, sinuous, laterally forming a "S"; pronotal fovea digitiform; mesepisternum with a evident dorsal groove; propodeum with longitudinal groove; T1 with shortened basal portion, approximately with the same length as the apical portion; lateral longitudinal carina evident and reaching the apical portion of T1; preapical fossa rounded; T2 longer than wide, with lamella; S2 without abrupt basal elevation.

Male genitalia. Not extracted for the preservation of the only known specimen of the species (the holotype).

Female unknown.

Type material: Holotype ♂ ( AMNH), Bolivia , Beni: ‘ BOLIVIA, Beni: Rio Itenez \ opposite Costa Marques \ (Brazil), Sept. 4-6, 1964 \ Bouseman & Lussenhop’ ‘ Pirhosigma \ sp.\ M.G.Hermes det. 2010’ (handwritten label).

Distribution. Known only from the type locality.

Etymology. The specific epithet refers to the holotype collection site, near the Itenez river, which limits the boundaries between the Brazilian state of Rondônia and Bolivia; treat as noun in apposition.

Figures

FIGURES 1 – 6. Pirhosigma transfluvium Ferreira & Oliveira new species, holotype male. 1. Habitus; 2. Head in frontal view; 3. Antennal apex; 4. T 1 in lateral view; 5. Metasoma in lateral view; 6. T 2 in dorsal view. Scale bar for Fig. 1 = 1 mm, Figs. 2 – 4 = 0.2 mm; Figs. 5 – 6 = 0.5 mm.

FIGURES 7 – 12. 7 – 11. Pirhosigma limpidum Giordani Soika, male. 7. Habitus; 8. Head in frontal view; 9. Antennal apex; 10. Metasoma in lateral view; 11. T 2 in dorsal view. 12. Pirhosigma pilosa (Fox), metasoma in lateral view. Scale bar for Fig. 1 = 2 mm, Fig. 8 – 9, 11 = 0.5 mm, Fig. 10, 12 = 1 mm.