Diadromus (Thyraeella) Wesmael, 1845

Rousse, Pascal, van Noort, Simon & Diller, E., 2013, Revision of the Afrotropical Phaeogenini (Ichneumonidae, Ichneumoninae), with description of a new genus and twelve new species, ZooKeys 354, pp. 1-85 : 27-28

Diadromus (Thyraeella) Wesmael, 1845

Thyraella Holmgren, 1890

Diagnosis.

Mandible bidentate, triangular and evenly narrowed towards apex, with a weak ventral flange, upper tooth twice as long as lower tooth; face transverse, wider than high; clypeus distinctly transverse, lenticular, hardly separated from face medially, its ventral margin somewhat impressed; occipital carina complete; occipital and hypostomal carinae joining at mandibular base; flagellum of female moderately enlarged and flattened beyond middle, flagellum of male without tyloids; epomia present and strong; mesoscutum steeply elevated above pronotum; postpectal carina complete and strong; propodeum moderately short, basal half about horizontal and apical half sloping down in lateral view; carination complete and strong, spiracle quite round; fore wing with areolet pentagonal, closed, 3 Rs–m non–tubular and faintly pigmented; hind wing with distal abscissa of Cu1 faint; gastrocoeli large and moderately deep; tarsal claws simple; thyridiae moderately weak but distinct, transverse and wide with interval narrow, distant from anterior margin by more than their width; hypopygium hiding base of ovipositor sheath; ovipositor very shortly projecting beyond metasomal apex.

Species richness and distribution.

Diadromus is a moderately large genus of 31 species, occurs almost worldwide, but has not been reported from South America or tropical Africa. The subgenus Thyraeella is highly unusual among the other species of the genus: it is mainly defined by the peculiar position of the junction between the hypostomal and occipital carinae, the complete postpectal carina and by having the ventral margin of the clypeus less impressed than in Diadromus s. s. The subgenus only includes the species Diadromus collaris .