Pycnomerinx Hull 1962
Creators: name: Londt, Jason G. H.
Publisher: name: Zenodo
Year: 1990
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Asilidae
Pycnomerinx

description: <i>Pycnomerinx</i> Hull, 1962 <i>Pycnomerinx</i> Hull, 1962:145. Type species: <i>Pycnomerinx annuialus</i> Hull, 1962 (= <i>Habropogon rhodesii</i> Ricardo, 1925), by original designation. Hull (1962) stated that <i>Pycnomerinx</i> is 'Related to <i>Scylaticus</i> Loew from which it is separated by the rather long though slender microsegment attached to the long, slender, third antennal segment, which is much shorter than in <i>Scylaticus</i> and more slender; also by the dense and quite long and extended mystax of the facial gibbosity and by the unusually long, large, swollen palpus. Second segment of the palpus densely covered below with long, coarse, bristly pile. First segment of all of the tarsi quite short, especially on the first four legs.' In my view the antennal differences alluded to are unconvincing in the light of variation within the two genera under discussion. The palpal characteristics are, however, diagnostically valuable. Heads dissected and cleared show only a single well-developed palpal segment (Figs I, 4). The fact that this segment lacks the terminal pit and internally associated 'gland' (present in most genera of the subfamily) suggests that <i>Pycnomerinx</i> may lack completely the second palpal segment. The overall length of tarsomeres are somewhat shorter than in <i>Scylaticus</i> but lengths of individual tarsomeres relative to each other do not show marked differences. In his key (couplet 55 A), Hull (1962) also points to differences in the setation of the scutellar margin; <i>Scylaticus</i> having ' 1 or 2 pairs of bristles' while <i>Pycnomerinx</i> has the 'whole posterior margin of the scutellum with an extensive, dense fringe of long bristles and bristly hairs'. The significance of this apparently good character will only be fully appreciated when a study of <i>Scylaticus</i> is completed. In the same couplet Hull also draws attention to a difference in venation; <i>Scylaticus</i> having the 'fourth posterior cell [cell m3] generally narrowed to half its maximum width' while <i>Pycnomerinx</i> has this cell 'open in its maximum width'. A preliminary assessment indicates that the genera do not demonstrate a clear difference with regard to the shape of cell m3 but again the importance of this feature will only be properly appreciated after a revision of <i>Scylaticus</i> has been done. For the time being I consider that the single-segmented palp represents the most reliable synapomorphic character for <i>Pycnomerinx.</i> The somewhat downturned, bow-shaped form of the labium (Fig. 1) also appears to be a potentially useful diagnostic feature of <i>Pycnomerinx</i> (as mentioned and illustrated by Oldroyd (1974)). Key to the species of <i>Pycnomerinx</i> Hull 1 All mesonotal microsetae yellowish, no darkly coloured ones present........ rhodesii (Ricardo, 1925) Mesonotum with a number of dark red-brown to black microsetae........ 2 2 Antennal macrosetae dark red-brown; T 3 entirely fine pruinose (golden in cJ', silvery in 2); wing membrane without slight staining adjacent to certain veins................................... " gweta Oldroyd, 1974 Antennal macrosetae white or pale yellow; distal half of T 3 silver pruinose (proximal half shiny black); wing membrane frequently with yellowish staining along certain veins............................ cogani Oldroyd, 1974
description: Published as part of <i>Londt, Jason G. H., 1990, Afrotropical Asilidae (Diptera) 20. The genus Pycnomerinx Hull, 1962 (Stenopogoninae), pp. 19-32 in ANNALS OF THE NATAL MUSEUM 31</i> on pages 21-22, DOI: 10.5281/zenodo.8383759
description: {"references": ["HULL, F. M. 1962. Robber flies of the World. The genera of the family AsiJidae. Bulletin of the United States National Museum 224 (1 - 2): 1 - 907."]}