Genus Thyridanthrax:
The genus Thyridanthrax is currently restricted to those species with hyaline areas within the infuscated part of the wing (fenestrate pattern); Hesse’s (1956) Group 2.
Wing normally developed; r-m crossvein at middle of discal cell, its terminal vein more or less parallel with wing margin; wing infuscation paler at base and with hyaline spots on crossveins (window panes).
Vestiture composed of black, brown, yellow and white elements; face with pale scaling; a distinct pale notopleural stripe; abdomen banded and with dense hair at sides of basal segments only.

Key to Afrotropical species available in:
Greathead, D. J. (1991). The genus Thyridanthrax Osten Sacken (Diptera: Bombyliidae) in tropical Africa. Insect Systematics & Evolution, 22(1), 45–54. doi:10.1163/187631291x00309
https://sci-hub.st/https://doi.org/10.1163/187631291X00309

Thyridanthrax laetus (Loew, 1860)
Diagnosis: Wing with three submarginal cells; extensive dark wing pattern extending almost to m-m and three clear angular spots centred on r-m, m-cu and cua,-cua2; discal cell usually completely infuscated. (Wing pattern is variable!) Most of the hair is bright golden-orange-reddish and there is a median stripe of black hair and scales on the abdominal tergites. Legs entirely orange.

Photo of wing in Greathead 1991: Figure 23
https://sci-hub.st/https://doi.org/10.1163/187631291X00309

Description by Loew:
https://www.biodiversitylibrary.org/item/35325#page/242/mode/1up
Illustration of wing, fig. 23: https://www.biodiversitylibrary.org/item/35325#page/349/mode/1up

Description by Hesse:
https://www.biodiversitylibrary.org/page/40844208#page/638/mode/1up

Distribution: South Africa, Botswana, Namibia, Zimbabwe, Malawi, Zambia, Tanzania, Kenya.

iNat observation:
https://www.inaturalist.org/observations/192815508

Posted on September 22, 2023 07:06 PM by traianbertau