Diadasina, Moure, 1950

Key to Species of Diadasina View in CoL

Females

1. Scopa loose ( Fig. 1 View Figures 1–6 ), scopal hairs on outer surface of hind tibia and basitarsus with few, long branches (up to 0.6 ˟ MOD) ( Fig. 3a View Figures 1–6 ); dorsal and ventral margins of hind tibia and basitarsus with stiff, simple hairs surpassing in length branched hairs ( Fig. 3b View Figures 1–6 ). Fourth segment of labial palpus truncate, with bifid apex ( Fig. 5 View Figures 1–6 ), last segment of maxillary palpus truncate. Vertex and dorsum of thorax with fulvous hairs. Erect hairs of T3–T4 usually black; prepygidial fimbria on T5 with black hairs ( Fig. 7 View Figures 7–10 )………………… D. distincta (Holmberg) View in CoL

—. Scopa dense ( Fig. 2 View Figures 1–6 ), scopal hairs on outer surface of hind tibia and basitarsus with numerous, shorter branches (up to 0.3 ˟ MOD) ( Fig.4a View Figures 1–6 ); dorsal and ventral margins of hind tibia and basitarsus only with branched hairs ( Fig. 4b View Figures 1–6 ). Fourth segment of labial palpus with rounded apex ( Fig. 6 View Figures 1–6 ); last segment of maxillary palpus with rounded apex. Vertex and dorsum of thorax with yellowish to grey hairs. Erect hairs of T3–T4 yellowish; prepygidial fimbria on T5 with yellowish, reddish or brown hairs ( Figs. 8–10 View Figures 7–10 )..................................................... 2

2(1). Apical bands of T3–T4 broad, that of T3 along midline 3 ˟ MOD ( Fig. 8 View Figures 7–10 ). Vertex of head much elevated behind ocelli ( Fig. 11 View Figures 11–12 ), distance from median ocellus to vertex in frontal view as long as 1.30–1.35 ˟ MOD............. D. singularis (Brèthes)

—. Apical bands of T3–T4 narrower, that of T3 along midline not over 2 ˟ MOD ( Figs. 9–10 View Figures 7–10 ). Vertex moderately elevated behind ocelli, distance from median ocellus to vertex in frontal view 0.65–0.80 ˟ MOD ( Fig. 12 View Figures 11–12 )................................. 3

3(2). Hairs on disc of scutum 0.7–1.1 ˟ MOD, on anterior surface of T1 1.0–1.2 ˟ MOD ( Fig. 9 View Figures 7–10 ). Pubescence of disc of T3–T4 very dense, hiding integument and obscuring basal limit of apical band ( Fig. 9 View Figures 7–10 ). Hind leg with yellowish brown tarsus and yellowish scopal hairs ( Fig. 9 View Figures 7–10 )................................. D. riparia (Ducke)

—. Hairs on disc of scutum 1.2–1.5 ˟ MOD, on anterior surface of T1 1.5–2.2 ˟ MOD ( Fig. 10 View Figures 7–10 ). Pubescence of disc of T3–T4 allowing to see dark integument below, so basal limit of apical band distinct ( Fig. 10 View Figures 7–10 ). Hind leg with black tarsus and brown scopal hairs ( Fig. 10 View Figures 7–10 ).................................................. D. tarijensis (Brèthes) View in CoL

Males

1. S6 with hairs loose along median longitudinal elevation and on apical third, not forming dense tuft; hairs shorter at sides of median elevation ( Fig. 13 View Figures 13–17 ). Flagellomeres 2–7 or 2–8 with raised, longitudinal ridges on plical surface, giving the antenna a weakly crenulate aspect ( Fig. 15 View Figures 13–17 )...................................... ........................................................................................... D. distincta (Holmberg) View in CoL

—. S6 with dense tuft of hairs on median longitudinal elevation, and bare at sides of it ( Fig. 14 View Figures 13–17 ). Flagellomeres cylindrical ( Figs. 16–17 View Figures 13–17 )............................. 2

2(1). Flagellomeres 2–4 shorter than their apical width ( Fig. 16 View Figures 13–17 ) (proportion 0.8– 0.9:1). Vertex much elevated behind ocelli, distance from median ocellus to vertex in frontal view 1.5–1.7 ˟ MOD (more elevated than in female, Fig. 11 View Figures 11–12 ).... .............................................................................................. D. singularis (Brèthes)

—. Flagellomeres 2–4 longer than their apical width ( Fig. 17 View Figures 13–17 ) (proportion 1.15– 1.20:1). Vertex moderately elevated behind ocelli, distance from median ocellus to vertex in frontal view 0.8–0.9 ˟ MOD (similar to that of female, Fig. 12 View Figures 11–12 )........................................................................................................................... 3

3(2). Hairs on disc of scutum 0.8–1.1 ˟ MOD. Flagellum reddish on underside. Pubescence of disc of T3–T4 dense, obscuring basal limit of apical band (as in female, Fig. 9 View Figures 7–10 )............................................................................ D. riparia (Ducke)

—. Hairs on disc of scutum up to 1.6 ˟ MOD. Flagellum black. Pubescence of disc of T3–T4 allowing to see dark integument below, so basal limit of apical band distinct (as in female, Fig. 10 View Figures 7–10 )............................................ D. tarijensis (Brèthes) View in CoL