Tenuopodinae Grichanov, 2018

Grichanov, I. Ya., 2018, A new subfamily of Dolichopodidae (Diptera) for Tenuopus Curran, 1924 with description of new species from Tropical Africa, Far Eastern Entomologist 365, pp. 1-25 : 3-4

Subfamily Tenuopodinae Grichanov , subfam. n.

Type genus: Tenuopus Curran, 1924 , here designated.

DIAGNOSIS. Single genus Tenuopus comprising 19 Afrotropical species. All the species examined and described have the following features. Long (5 to 10 mm),

mostly yellow body; head with the strongly excavated vertex on either side of the ocellar tubercle; one pair of ocellar, occipital and postvertical bristles; vertical setae absent; proboscis with a pair of black lateral setae and yellow hairs; scape bare,

pedicel with digitiform inner projection upon postpedicel, more developed in males;

arista-like stylus dorsal, short pubescent. Mesonotum convex, no mesoscutal flattening; six or seven dorsocentral bristles with first bristle somewhat smaller;

scutellum with two strong bristles. Legs mostly yellow, coxae with yellow hairs and black bristles, hind coxa with one external bristle; mid and hind femora usually with one preapical seta. Wing vein R 2+3 reaches costa in apical fifth of wing, being nearly parallel with R 4+5; M 1 with gentle arc to apex, reaching costa before wing apex, near R 4+5; M 2 usually present as fold on membrane; dm-m straight, bm-m

reduced. Abdomen of six segments with strong marginal bristles, without tergal window in segment 1, and with less sclerotised “pseudotergite” between segments 1

and 2 (see Parent, 1938; Bickel, 1994); seventh segment and hypopygium small,

epandrium partly concealed; cercus usually short and simple, surstylus usually long,

often bifurcated; at least one very long and a few short epandrial lobes.

NOTES. The general habitus and male terminalia of Tenuopus suggest its pla-

cement in the Neurigoninae , and the genus has historically been assigned to the latter subfamily, but unlike neurigonines, species of Tenuopus have the thorax with the posterior mesonotum convex and the mid and hind femora usually each with anterior preapical seta (similar to Peloropeodinae ). Peloropeodine genera includes rather small representatives (1 to 3 mm) with posterior mesonotum distinctly flattened and slightly depressed, wing veins R 4+5 and M 1 subparallel, and M 1 nearly straight (e.g., Bickel, 2009; Grichanov & Brooks, 2017), strongly differing from both Tenuopus and Neurigoninae by these and other features. Tenuopus and most

Sciapodinae share such characters as vertex of head strongly excavated on either side of ocellar tubercle, wing vein M 1+2 distinctly branched, with vein M 2 present at least as a fold in membrane (vein M 2 absent in species of the sciapodine tribe Meso-

rhagini); thorax with mesonotum usually short, about as wide as long; posterior mesonotum not flattened. Grichanov & Brooks (2017) considered Tenuopus as a genus incertae sedis, distinguishing it from Sciapodinae by the following combination of characters: head without vertical setae in both sexes; antennal pedicel forming short thumb-like projection on inner side of postpedicel; abdominal segment 1

without tergal window; male terminalia with hypopygium mostly exerted, but with small segment 7; hypandrium strongly reduced. In this paper I consider the listed diagnostic characters of Tenuopus as having importance at the family level, being significant for the establishment of a new subfamily Tenuopodinae , even more significant than characters used recently for substantiation of some new dolichopodid subfamilies (e.g., Yang et al., 2006).