Tetraglossula bigamica

Tetraglossula bigamica (Strand, 1910)

(Figs 8, 9, 14 E–H, 15D–F, 17B,F, 18C,D)

Bicolletes bigamica Strand, 1910, 463. Type depository: holotype ZMB ♂, (examined); type locality: Paraguay, Asunción. Tetraglossula bigamica; generic combination by Moure 1951.

Bicolletes stigmatica Strand, 1910: 464. Type data: holotype ZMB ♀. Type locality: Paraguay, Sapucay. Moure, Graf & Urban 1999, new synonymy.

Tetraglossula birabeni Oglobin, 1948, 169. Type data: holotype MLP ♂; type locality: Argentina, Misiones, Pindapoy. Synonymy proposed by Moure (1951: 191).

Leioproctus (Tetraglossula) bigamicus; generic combination by Michener 1989.

Leioproctus (Tetraglossula) stigmaticus; generic combination by Michener 1989.

Taxonomic note: Moure et al. (1999) were the first to indicate the presumable doubt of Strand in assuming Bicolletes bigamica (described based on a male specimen) and B. stigmatica (represented by a female specimen from a locality less than 100 km away). Strand's (1910, 464) only remark on B. stigmatica was as follows: "Bei der großen Ähnlichkeit der Arten dieser Gattung ist es durchaus nicht ausgeschlossen daß dies ♀ einer andern Art angehört; diese möge eventuell den Namen B. stigmatica m. bekommen."

Diagnosis. This species and T. deltivaga are distinct from the remaining Tetraglossula species for the small to moderate body size (<10 mm; usually 7–9 mm), dark metasoma, and the pale to whitish pubescence on mesosoma. Punctation on disc of scutum of female moderately sparse, but denser near median and parapsidial lines (on scutum of female of T. deltivaga, punctation evenly sparse on disc of scutum—Fig. 16B); metapostnotum of T. bigamica longer than metanotum (Fig. 17 B,F), whereas in T. deltivaga these surfaces have the approximate same length (Fig. 17 C,G)—the demarcation of the metapostnotum of females of T. bigamica is unique within Tetraglossula because the pits are fossulate (foveate in other species). The male S7 of T. bigamica has a uniquely shaped basal lobe (Fig. 14 F; see comments below).

Male genitalia and hidden sterna S6–S8: Figs 14 E–H, 15D–F. Line drawings of the male Tetraglossula birabeni type (S6–S8 and genitalia) can be found in Ogloblin (1948, Figs 13–15). Basal lobe of S7 (Fig. 14 F) large, broad, pilose, and complex in shape (outer basal edge curly reentrant, forming a basal projection that follows the orientation of the apodeme), completely superposed with the apical lobe—the latter only visible in transparence in dorsal view; medial sclerotized region positioned proximally to the apical and basal lobes of S7 short. Apical lobe of S8 as long as or slightly longer than disc of S 8 in profile (Fig. 14 H).

Distribution (Fig. 19): ARGENTINA: Buenos Aires (Tandil [MLP:1]), Catamarca (San Fernando del Valle de Catamarca [SEMC:1]), Tucumán (Acheral [AMNH:6]); BRAZIL: Mato Grosso (Corumbá [RPSP:1]), Mato Grosso do Sul (Porto Murtinho [RPSP:6]), Rio Grande do Sul (Camaquã [RPSP:1, DBAI:1], Rosário do Sul [RPSP:17, DBAI:3]); PARAGUAY: Asunción [ZMB:2]. These records indicate a distribution in the Pampas and Chaco biomes, but with some remarkable disjunctions between some areas (lack of records is particularly noticeable in northeastern Argentina, Uruguay and parts of southern Brazil), which could be due to collecting biases. Analysis of genitalia and hidden sterna from the most extreme distribution records did not indicate significant morphological differences among specimens herein treated as T. bigamica.