Diadasina tarijensis (Brèthes)

Diadasina tarijensis (Brèthes) View in CoL

( Figs. 10 View Figures 7–10 , 18–22 View Figures 18–22 , 23 View Figures 23-24 )

Leptometria tarijensis Brèthes, 1910: 298 View in CoL . Holotype male, Bolivia, Tarija, MACN, examined.

DIAGNOSIS: This species is morphologically similar to D. riparia , from which it is distinguished by the longer pile on the mesosoma and the base of T1. Furthermore, unlike D. riparia , the short hairs on the terga do not conceal the integumental surface, so there is a sharp contrast between the preapical part of the terga and the dense apical yellow bands. The scopal hairs on the tibia and basitarsus, as well as the prepygidial and pygidial fimbriae of the female, are dark brown. The male antenna is entirely black.

REDESCRIPTION: Female. Length, 8.5 mm; length of forewing 7.0 mm. Black, except reddish distitarsi; tegula dark brown. Pubescence greyish on head, mesosoma, most of legs, and base of T1, although somewhat tawny on vertex of head and dorsum of thorax. Scopal hairs on hind tibia and basitarsus, minute hairs on basal part of T2– T5, and hairs of prepygidial and pygidial fimbriae, brown. Apical bands on sides of T1 and on T2–T4, yellow. Hairs on scutum 1.2–1.5 ˟ MOD; on mesopleuron 2.2–2.8 ˟ MOD. Hairs on outer side of forebasitarsus bearing numerous short branches; hairs on outer side of hind tibia and basitarsus plumose. T1 at sides and T2–T4 with sharply defined apical band of dense, appressed hairs; bands on T3–T4 narrow, that on T3 along midline 1.5 ˟ MOD. Scutum with punctures dense, on disc separated by 0.5– 1 ˟ puncture diameter. Eyes weakly convergent below, proportion of upper to lower interocular distance, 1:1.09. Vertex moderately elevated behind ocelli, distance from median ocellus to vertex in frontal view 0.7 ˟ MOD. Last segment of labial and maxillary palpi parallel-sided, with narrowly truncate apex.

Male. Length, 7.0– 7.5 mm; length of forewing 6.0– 6.5 mm. Color and vestiture similar to that of female, although hairs longer, those on scutum 1.6–2.0 ˟ MOD. With well-defined apical bands on T2–T6, that on T3 along midline 1.5 ˟ MOD. S6 with dense tuft of hairs on median longitudinal elevation, and bare at sides of it. Vertex moderately elevated behind ocelli, distance from median ocellus to vertex in frontal view 0.9 ˟ MOD. Flagellum not crenulate, proportion of four proximal flagellomeres 1:1.4:1.4:1.4; first flagellomere 0.9 ˟ as long as its apical width, following three flagellomeres longer than their apical width (1.17 ˟).

COMMENTS ON TYPE MATERIAL: The male holotype is in good condition, although somewhat discolored. It bears the labels: “ Tarija ” “ Leptometria / tarijensis Br. ” and “ Holotypus.”

DISTRIBUTION: Bolivia, departments of Cochabamba, Santa Cruz and Tarija .

MATERIAL STUDIED: Bolivia. Cochabamba: 1 F, 19 M, Cochabamba, R. Zischka ( MLP) ; 1 M, Cochabamba, 15.iv.1951, Zischka ( SEMC) . Santa Cruz: 1 M, Estación Experimental General Saavedra , 9.vii.1972, C. Porter & L. Stange ( IFML) ; 1 M, P. Cordillera, Río Seco , ii.1959, A. Martínez ( DZUP) . Tarija: 1 M, Tarija, holotype of Leptometria tarijensis Brèthes (MACN) ; 2 M , Tarija, 20.iii.1968, J. Ballard ( SEMC) .