Dasophrys tarsalis (Ricardo, 1920)

Londt, Jason G. H., 2020, A survey of grassland Asilidae (Diptera) at Jacana Eco Estate, Hilton, South Africa, African Invertebrates 61 (1), pp. 29-48 : 29

9. Dasophrys tarsalis (Ricardo, 1920) Fig. 7

Remarks.

Afrotropical Dasophrys Loew, 1858 were revised by Londt (1981), with tarsalis being recorded from a number of localities in KwaZulu-Natal, situated mainly in the so called ‘midlands’ which lie a short distance north-west of Hilton. However, the nearest recorded locality to Jacana is 'The Start’, a stud farm ca. 20 km NE of Howick (ca. 29°23'57"S, 30°17'21"E). Its occurrence at Jacana Eco Estate was unexpected, but hardly surprising.

Adults of this species were common to abundant between the late autumn weeks 12 and 18. None were encountered in weeks 19 and 20, while a single specimen was found in week 21. All specimens were collected in the lower field.

This moderately large species was almost invariably encountered flying fairly close to the ground where individuals perched on low vegetation. None were encountered mating or with prey. The species appears to be largely confined to Londt’s (1994) ecological category 4a (within grass). The female’s laterally compressed ovipositor is probably an adaptation for oviposition in grass.

Figures

Figures 4 - 13. Grassland inhabiting Asilidae encountered at Jacana Eco Estate (arranged alphabetically): 4 Caenoura annulitarsis (Loew, 1858) 5 Damalis monochaetes Londt, 1989 6 Dasophrys fortis Londt, 1981 7 Dasophrys tarsalis (Ricardo, 1920) 8 Dysclytus firmatus (Walker, 1857) 9 Euscelidia vallis Dikow, 2003 10 Ischiolobos mesotopos Londt, 2005 11 Leptogaster sp. 12 Microstylum sp. 13 Rhipidocephala obscurata Oldroyd, 1966. Photos: B. Muller.