Caenoura annulitarsis (Loew, 1858)

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

4. Caenoura annulitarsis (Loew, 1858) Fig. 4

Remarks.

This fairly widely-distributed grassland species was reviewed by Londt (2002a). Found mainly in KwaZulu-Natal, the species has also been recorded from the surrounding provinces of Eastern Cape, Free State and Mpumalanga, as well as the neighbouring countries of Lesotho and Zimbabwe. Londt (2002a) gives adult activity data that includes all months from November to May, based mainly on material gathered during a grassland survey undertaken in 2000 at Queen Elizabeth Park (29°34'S, 30°19'E) in Pietermaritzburg ( Londt 2002b).

At Jacana, adults of this species were encountered in low numbers on week five of the survey. By week eight, numbers had increased and by week 11, the species was considered abundant. Numbers began to decline from week 16 and the species had disappeared by week 21; the total flight period of adults being 16 weeks. The species was more commonly encountered in the upper field.

This relatively small species was invariably swept from grass with very few actually being sighted. None were encountered mating or with prey. The species appears to be largely confined to Londt’s (1994) ecological category 4a (within grass).

Table 4 provides a comparison of flight periods with those recorded from Queen Elizabeth Park ( Londt 2002b). Adults were encountered at approximately the same time of year, but flight periods ranged from 16 weeks at Jacana to 25 weeks at Queen Elizabeth Park.

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.