In the key to South African Dasiops species (McAlpine
1960) the only species with a combination of white fringed calypteres, partly yellow
tarsomeres and lunule lacking pock-like depressions are D. rugicavus McAlpine,
1960 and D. concavifrons McAlpine, 1960. Both of these species have hairy or
pubescent eyes and their aculeus, although broad, does not have an apical segment
with straight sides and an acute apex and both are easily distinguished from D.
Description: Female. Head: Eyes bare. Frons shining blue-black, frons to eye
width ratio 1:1, frontal and interfrontal setulae 0.5× as long as orbital setae, a few
small pock marks at base of interfrontal setulae, shallow lateral depression present
on frons just anterior to ocellar plate. Lunule, ground colour slightly brown, flat
apart from slight medial depression between antennal bases. Antennae black, postpedicel
length to depth ratio 1:0.7. Arista microscopically pubescent, yellow basally.
Anterior genal setulae in a row of three along mouth margin, posterior to these a
single strong seta twice as long and strong as the other genal setulae.
Thorax: Scutum sub-shining blue black, covered with rather sparse pilosity 0.5×
as long as the orbital seta. Anepisternum with two anterior setae and three posterior
setae, one post-stigmatical seta. Katepisternum with one seta located near
dorsal margin. Scutellum, bare apart from four marginal setae. Proepimeron and
proepisternum each with one seta. Calypteres white with a white fringe. Wings clear,
veins yellow, wing length 2.5 mm. Legs black, all basal and second tarsomeres
Female terminalia: Aculeus broad, 0.5× width of the base of tergite five, smoothly
rounded apically. Apical segment parallel sided, embedded in aculeus base, acutely
angled at apex, with three short lateral setulae, apical segment length to width ratio
2.75:1, parallel sided with acute 60° apex.