A review of the genera Anasillomos Londt, 1983, Oratostylum Ricardo, 1925, and Remotomyia Londt, 1983, with description of a new genus and two new species (Diptera: Asilidae: Stenopogoninae)
Author
Torsten Dikow
Author
Jason G. H. Londt
text
Ann. Natal Mus.
2000
41
107
121
journal article
10.5281/zenodo.11581
Oratostylum crenum
sp. n.
(Figs 8-10, 14-15, 19)
Etymology: L. crena = rounded projection. Refers to the rounded appearance of the facial swelling.
Description (based on all material examined):
Head: Antenna orange-brown; postpedicel clubbed (Fig. 15) and longer than scape and pedicel combined; scape and pedicel with anteriorly directed yellow setae; style cylindrical, black; face orange-brown with dense golden (
♀
) or silvery (
♂
) pruinescence; mystax yellow, some black setae on upper margin; facial swelling pronounced, not ending abruptly in upper part (Fig. 14); vertex black and silver-gold pruinose, yellow setae laterally, ocellarium prominent with 4-6 yellow setae; occiput black with silvery pruinescence, yellow and white setae; proboscis black, stout, ventrally with white setae; palpi black, longer than half length of proboscis, white setae ventrally.
Figs 14-18. Fig. 14. Head of
Oratostylum crenum
sp. n.
, lateral view. 15-18. Postpedicel of
Oratostylum
and
Ontomyia
. 15.
Oratostylum crenum
sp. n.
16.
Oratostylum zebra
sp. n.
17-18.
Ontomyia ricardoi
(Londt, 1985). Scale lines =
1 mm
.
Thorax
: Orange-brown; pronotal setae yellow and white; propleuron with white setae only; postpronotal lobe with yellowish setae of different lengths; mesonotum:
♀
brown pruinose,
♂
grey pruinose, 2 longitudinal stripes not reaching hind margin (
♀
brown,
♂
black), covered with short white and brownish setae (longer in
♂
), 1-2 pairs dorsocentral setae may be present anterior of transverse suture, macrosetae yellow; scutellar pruinescence similar to that of mesonotum, disc with yellow setae, margin with 6-8 yellow setae; mesopleura:
♀
dorsally brown pruinose and ventrally grey pruinose,
♂
entirely grey pruinose, white setae only; katagergal setae yellow; anatergal setae yellowish; legs: coxae orange-brown with silvery pruinescence and white setae; fore femur orange-brown, posteroventrally black, fore and hind tibiae with dense short yellow setae on inner margin which extend onto basitarsi, these setae only on distal half of hind tibia; mid and hind femora orange-brown, black ventrally, all tibiae proximally orange-brown, black distally; tarsi black; all macrosetae of legs pale yellow; claws brown basally and black distally, pointed; pulvilli large, pale yellow; empodium needle-like, black; wing: membrane transparent; veins yellow basally and on anterior margin, distally brown; r
5
open, m
3
open; halteres pale yellow.
Abdomen: Brown; T1 with long white setae and a few pale yellow setae laterally; remaining terga with white and yellow setae; pruinescence silver-brown with silvery hind margin, apruinose diagonal stripes laterally; sterna weakly silver pruinose with white setae; T6-8 of
♀
apruinose, brown with white, erect fine setae; macrosetae of acanthophorites reddish-brown;
♂
genitalia orange with white setae, hypandrium without distal projection (Figs 8-10).
Material examined: SOUTH AFRICA:
1♂
holotype
, 'S Africa: N-W Province / Pilanesberg National Park / Manyane Trail
15.xi.1999
/
25°15'12"S
:
27°13'25"E
/ J.G.H. Londt 1200
m'
(
NMSA
);
3♂
2♀
paratypes
, 'S Africa: N-W Province / Pilanesberg National Park / Manyane Trail
15.xi.1999
/
25°15'12"S
:
27°13'25"E
/ J.G.H. Londt 1200
m'
(
NMSA
);
1♀
paratype
, 'S Africa: N-W Province / Pilanesberg National Park / Bakubung
12-19.xi.1999
/
25°20'40"S
:
27°03'25"E
/ J.G.H. Londt
1170m
camp'
(
NMSA
);
1♂
1♀
paratypes
, 'S Africa: N-W Province / Pilanesberg National Park / Bakubung
12-19.xi.1999
/
25°20'40"S
:
27°03'25"E
/ J.G.H. Londt
1100m
gate'
(
NMSA
).
Remarks: The sexual dimorphism displayed by this species is remarkable. The pruinescence of the mesonotum, mesopleuron, and face differs - females tend to be more golden pruinose whereas males are silver-grey pruinose.