Polynemula Ogloblin, 1967

Triapitsyn, Serguei V. & Aquino, Daniel A., 2008, Redescription of Polynemula, with description of a new species of Polynema (Doriclytus) from Argentina (Hymenoptera: Mymaridae), Zootaxa 1818, pp. 56-64 : 57-58

Polynemula Ogloblin, 1967

( Figs 1–5 )

Polynemula Ogloblin 1967: 190 . Type species: Polynemula rufosignata Ogloblin , by original designation. Polynemula Ogloblin : De Santis 1979: 376 (catalog); Yoshimoto 1990: 15 (key), 67–68 (brief diagnosis and discussion, list of species; incorrectly stated that only a single female is known).

Redescription. FEMALE. Body length 1.1–1.3 mm. Body ( Fig. 2 ) and appendages light to dark brown.

Head a little wider than mesosoma. Face with a pit next to each torulus ( Fig. 2 ). Mandible 3–dentate.

Antenna ( Fig. 1 ). Scape smooth on both surfaces; funicle 6–segmented, with all segments notably longer than wide and without longitudinal sensilla; clava entire, with 7 longitudinal sensilla.

Mesosoma ( Figs 2, 3 ). Propleura abutting each other anteriorly along midline, the prosternum thus closed anteriorly; pronotum partially divided mediolongitudinally (anteriorly only) [not visible in Fig. 3 but well illustrated by Ogloblin (1967)]; axilla not well differentiated; scutellar sensilla a little closer to anterior margin of scutellum than to row of frenal foveae; propodeum with 2 subparallel submedial carinae, diverging and elevated anteriorly (best seen in lateral view) and connected by a weaker transverse carina close to propodeal anterior margin; lateral carinae incomplete and inconspicuous.

Wings ( Fig. 5 ). Marginal vein of forewing elongate, with two dorsal macrochaetae; forewing disc more or less uniformly setose, with a faint infumation (a cross-band) beyond venation. Hind wing disc inconspicuously infumate medially.

Metasoma ( Fig. 2 ). Petiole attached to gastral tergum, a little longer than wide; gaster ( Fig. 4 ) elongate; ovipositor strongly projecting anteriorly underneath mesosoma, extending up to posterior margin of prosternum, and notably protruding beyond gastral apex (by 1/7–1/5 of ovipositor length).

MALE. Unknown.

Diagnosis. The ovipositor strongly produced anteriorly underneath the mesosoma makes recognition of Polynemula quite easy among the Neotropical Polynema -group genera, although this character occurs in several other (unrelated) genera of Mymaridae , such as Gonatocerus Nees. Among the Neotropical Polynema - group genera, however, only in Platypolynema Ogloblin the ovipositor is also strongly produced anteriorly, but unlike Polynemula , Platypolynema lacks a pit near each torulus and has distinct V-shaped subantennal grooves on the face and a characteristic forewing ( Triapitsyn & Berezovskiy 2002). Yoshimoto (1990) mistakenly included the presence of subantennal grooves on the face in his brief diagnosis of Polynemula . The genera Platyfrons Yoshimoto (Neotropical, occurring at high altitudes only), Himopolynema Taguchi (Oriental, Palaearctic, and Australasian), and the subgenus Polynema (Doriclytus) (almost cosmopolitan except for Australia and New Zealand) have a pit near each torulus and the prosternum closed by propleura anteriorly, as in Polynemula . No other Neotropical Polynema -group genus of Mymaridae has this combination of characters except for Xenopolynema Ogloblin , but the latter has a short ovipositor, a broadened petiole, semicircular carinae on the propodeum, and the forewing disc with a conspicuous darkening below marginal vein (demarcating the archaic basal vein) ( Triapitsyn & Berezovskiy 2007). However, each of these genera has a distinctive arrangement of carinae on the propodeum: in Polynemula , the two submedial carinae are subparallel, diverging and elevated anteriorly, and connected by a weaker transverse carina close to the anterior margin of the propodeum; in Himopolynema , the two submedial carinae can be either far apart or close to each other and are not connected; in Platyfrons , the submedial carinae are H-shaped; in Polynema (Doriclytus) , the propodeum can be either without carinae, with an incomplete or complete medial carina, or (as in the pallidiventre species group) with transverse wrinkles and two short, incomplete submedial carinae at the posterior margin of the propodeum. At this point, without a rigorous phylogenetic analysis and availability of molecular data on these taxa, any discussion on their possible relationships would be highly speculative. Links with Platyfrons and the pallidiventre species group of Polynema (Doriclytus) , however, are most likely; the similar wing structure and somewhat similar submedial carinae on the propodeum in Platyfrons may warrant synonymy of that genus under Polynemula in the future. Hovewer, all species of Platyfrons have a normal, relatively short ovipositor and occur only at high altitudes in the Neotropics whereas Polynemula is known only from the lowlands in Buenos Aires area in Argentina. Therefore, at present at least, proposing synonymy of Platyfrons under Polynemula would be premature.

Distribution. Argentina.

Hosts. Unknown.

Figures

FIGURES 1 – 5. Polynemula rufosignata, female. 1. Antenna without scape (holotype). 2. Body (lateral view, paratype). 3. Mesosoma (holotype, pronotum not entirely visible). 4. Gaster (ventral view, holotype). 5. Wings (holotype).