Nanium Townes, 1967

Reshchikov, Alexey, Sääksjärvi, Ilari E. & Pollet, Marc, 2018, Review of the New World genus Nanium Townes, 1967 (Hymenoptera: Ichneumonidae: Ctenopelmatinae), with two new species from the Neotropical region, European Journal of Taxonomy 459, pp. 1-18 : 3-4

publication ID	https://doi.org/10.5852/ejt.2018.459
publication LSID	urn:lsid:zoobank.org:pub:7F198F1E-A4F6-457E-9E03-667D709C35DD
DOI	https://doi.org/10.5281/zenodo.14611206
persistent identifier	https://treatment.plazi.org/id/03E387CE-FFE1-CB75-F768-FC0FFA83F862
treatment provided by	Plazi
scientific name	Nanium Townes, 1967
status

Treatment

Genus Nanium Townes, 1967 View in CoL View at ENA

Nanium Townes, 1967: 174 View in CoL –175.

Type species

Tryphon capitatus Cresson, 1864 , by original designation.

Diagnosis (Updated from Townes 1970)

Generally small-bodied species (3–6 mm), similar to the smaller species of Lathrolestes . Can be distinguished from the latter by the absence of propodeal carinae, except occasional traces of median longitudinal carinae posteriorly, and by the granulate sculpture on the propodeum and T1. In contrast with other genera of Perilissini , the epicnemial carina in Nanium extends to the anterior margin of the mesopleuron, the pterostigma is short and the marginal cell is also short and deep. The genus can further be characterized as follows: clypeus with ventral margin thick and bluntly rounded, thinner laterally, without small lateral tooth or projection. Ventral margin of clypeus convex. Epistomal sulcus usually distinctly present. Clypeus in profile not projecting or only very weakly angled outwardly from face. Malar space distinct, from very short (0.2 × basal width of mandible) to moderately long (0.3–0.5 × basal width of mandible). Diameter of lateral ocellus much shorter than the distance between ocellus and eye. Maxillary palp moderately long, about equal to head height. Female antenna ranging from as long as to slightly, but distinctly, longer than body. Occipital carina dorsally complete, its lower part joining hypostomal carina distinctly above base of mandible. Dorsal end of epicnemial carina extending to anterior margin of mesopleuron. Notaulus varying from nearly absent to distinctly impressed on anterior declivity, extending posteriorly to level of tegula as a weak groove. Groove present between propodeum and metanotum indistinct in lateral view. Propodeal carinae usually completely absent (occasionally traces of median longitudinal carinae). Apex of mid tibia somewhat evenly rounded, with at most a small, weak tooth (similar to several species of genus Perilissus Förster, 1855 ). Apex of hind tibia with poorly developed comb, with setae widely spaced, not dense. Posterior hind tibial spur at least 7 × longer than maximum width at base. Claws varying from completely pectinate to pectinate only in basal half. Fore wing nearly always with vestigial areolet. Pterostigma short, broad, with Rs +2 r arising near middle of pterostigma. Hind wing with first abscissa of M + Cu 1 strongly bowed; distal abscissa of Cu l not always discernible but when visible, joining cu-a closer to l A than to M; distal abscissae of 1 A and Cu l spectral, vestigial or absent. T1 varying from moderately long and slender to shorter, distinctly broadening posteriorly and flattened dorsally. Dorsal carinae absent. Basal depression at dorsal tendon attachment absent. Dorsal-lateral carina absent or nearly so between spiracle and apex of T1. Glymmae on each side meeting on the midline posterior to dorsal tendon attachment, large, deep, and separated at midline by translucent partition. T2 with thyridium absent. Ovipositor straight, short, with very broad, deep, subapical depression. Ovipositor sheath from narrowly rectangular to weakly expanding distally. Male parameres broad, rectangular, never strongly narrowed posteriorly. Aedeagus rounded and weakly clubbed distally.

Identification key to the species of Nanium

1. Face distinctly broader than high ( Figs 2A View Fig. 2 , 3A View Fig. 3 , 5A, 6A)...........................................................2 − Face at most about as broad as high ( Fig. 1A View Fig. 1 ) ................................................................................. 5

2. Mesosoma with yellow stripes anteriorly on mesoscutum ( Fig. 5C View Fig. 5 ). Metasoma with all tergites extensively pale medially ( Fig. 5B View Fig. 5 ) ....................... N. medianum Reshchikov & Sääksjärvi sp. nov.

− Mesosoma black dorsally and yellowish ventrally, or entirely black ( Figs 2B View Fig. 2 , 3C View Fig. 3 , 6C, 7C). Metasoma entirely black, with only T3 extensively pale, or with tergites black with hind margins narrowly yellow ( Figs 2B View Fig. 2 , 3B View Fig. 3 , 6B, 7B) ........................................................................................................... 3

3. Metasoma with T3 extensively pale ( Figs 2B View Fig. 2 , 3B View Fig. 3 ), and T2–4 uniformly dark ( Fig. 3B View Fig. 3 ) .................... .. .................................................................................................................. N. capitatum Townes, 1967

− Metasoma with T3 concolorous with T2–4 ( Figs 6B View Fig. 6 , 7B View Fig. 7 ) ................................................................... 4

4. Mesoscutum strongly polished and rather smooth. T1 about 1.5 × as long as broad posteriorly ( Fig. 6B View Fig. 6 ) ........................................................................................................ N. nogueri Gauld, 1997

− Mesoscutum granulate. T1 about 2.3 × as long as broad posteriorly ( Fig. 7B View Fig. 7 ) .................................. .......................................................................................................................... N. oriasi Gauld, 1997

5. Pleural carina distinct. T1 less than 2.4 × as long as broad posteriorly ( Fig. 1A View Fig. 1 ); hind coxa, at least partly, yellowish ( Fig. 1C View Fig. 1 ) ................................................................................................................ 6

− Pleural carina absent. Metasoma with T1 at least 2.8 × as long as broad posteriorly; hind coxa nearly entirely black .............................................................................................. N. mairenai Gauld, 1997

6. Antenna with 26 flagellomeres. Hind tibia 9 × as long as broad apically. Ovipositor sheath diamond-shaped. Propleuron yellowish. T3 yellowish with dark anterior part. Hind coxa entirely pale yellow. Hypopygium pale yellow ( Fig. 4 View Fig. 4 ) ................................................................ N. huberthi Gauld, 1997

− Antenna with 28 flagellomeres. Hind tibia 7 × as long as broad apically. Ovipositor sheath gradually expanding towards apex. Propleuron dark brown ( Fig. 1C View Fig. 1 ). T3 entirely yellowish ( Fig. 1B View Fig. 1 ). Hind coxa dark brown with only its basodorsal part pale yellow ( Fig. 1C View Fig. 1 ). Hypopygium dark brown ( Fig. 1C View Fig. 1 ) ................................................................ N. atitlanensis Reshchikov & Sääksjärvi sp. nov.