Rhyncomya pruinosa Villeneuve, 1922

Thomas-Cabianca, Arianna, Villet, Martin H., Martinez-Sanchez, Anabel & Rojo, Santos, 2023, South African nose flies (Diptera, Calliphoridae, Rhiniinae): taxonomy, diversity, distribution and biology, Biodiversity Data Journal 11, pp. 72764-72764 : 72764

Rhyncomya pruinosa Villeneuve, 1922

= Rhyncomya pruinosa Villeneuve, 1922: 65. Type locality: Kenya, Zaire [Democratic Republic of Congo], Nyasaland [Malawi]; Anglo-Egipsian Sudan [Sudan].

Distribution

Afrotropical: Angola, Botswana, Cameroon*, Democratic Republic of Congo, Ethiopia*, Gambia, Kenya, Malawi, Mauritania*, Mozambique, Namibia, Nigeria, Senegal*, South Africa (Fig. 105 ), Sudan, Zambia and Zimbabwe.

Notes

Preferred environment: Dry, sand and broad-leafed deciduous forest and Acacia savannah. In Cameroon, in degraded savannah forest. In Namibia, in Miombo and Mopane Woodlands, Arid and Mesic Savannah and Nama-Karoo Biomes ( Kurahashi and Kirk-Spriggs 2006). Recorded elevations: 53-1086 m a.s.l. Seasonality: absent from January to March, May and October, present in low numbers the rest of the months, peaking in December. In Namibia, most abundant in October and December ( Kurahashi and Kirk-Spriggs 2006). Behaviour and ecology: Cuthbertson (1933) observed in Balla Balla (now Mbalabla), Zimbabwe, that males are scarce and found in flowers and females are very active in late afternoon around cattle kraals, newly-ploughed fields and places in Mopane forest under trees where soil had been dug up by the species in search of larvae. Females were observed depositing eggs into soft soil by thrusting their ovipositors inside and moving at the same time in Zimbabwe ( Cuthbertson 1933). Peris (1952b), also in Zimbabwe, recorded females laying eggs in "svil at noots" and grass attacked by termites. Life cycle and developmental stages: oviparous. Eggs, larva and pupa known ( Engel and Cuthbertson 1937). Engel and Cuthbertson (1937) indicate that: "The eggs are deposited singly in soft soil under the shade of trees, in sandy pathways in savannah forest or in the powdery dung and sand of cattle kraals. The eggs are about 1.75-2 mm. in length, elongate oval, the chorion faintly marked with microscopical reticulations. The female sometimes has a curious habit of filling in the hole made during egg-laying with soil by means of the hind legs, and sometimes by means of the tip of the ovipositor which she uses as a broom. An examination of the egg laying tube has revealed the presence of an armature of spines, which may be similar in function to the spines on the ovipositor of the Asilid. The eggs are usually fully incubated at the time of extrusion, and the newly hatched larvae are very active. They inhabit the top three or four inches of soil, and are often associated there with worker termites, and the pupae of coprophagous beetles and flies. The larvae usually are fully grown when about seven to ten days old. The puparia are found in the soil, usually about four inches beneath the surface. The pupal period is about 7-9 days in the warm weather of the wet season, but is much longer in the cold weather of June and July, about two weeks. The number of eggs laid by this species is not known. Dissections of the female reproductive organs have revealed, in sexually mature individuals, about ten large ovarioles (1.5 mm. in length) in each ovary". Cuthbertson (1933) notes that eggs are covered with a sticky secretion that camouflages them by the attachment of soil particles. Incubation period was around 18 hours. He also observed that larvae are active and live near the soil surface during cool hours of the morning and towards sundown, but retire to the greater depths during the heat of the day. The larvae were found in large numbers in soil under termite-infested dung patches in shade during March and April. The duration of the larval stages varies from 7-10 days. Mature larvae measure 12-15 mm. Their prey is presumably dipterous larvae and pupae or termites which live in their habitat. The pupal stage lasts 7 days in mid-December and 7-10 days in May. Engel and Cuthbertson (1937) illustrated the immature stages. Collection methods: sweep net, with light, yellow pan and Malaise traps. In Botswana, Cameroon and Zambia, it was collected with Malaise traps. In Namibia, it was collected with pitfall and Malaise traps and attracted by UV light ( Kurahashi and Kirk-Spriggs 2006). Illustrations and photographs: male habitus as in Fig. 106 . Male terminalia as in fig. 55 in Zumpt (1958).

Material examined: Suppl. materials 1, 2.

Figures

Figure 105. Rhyncomya pruinosa occurrence map in South Africa, including eSwatini (eSw) and Lesotho (Le); horizontal axis longitude east and vertical axis latitude south.

Figure 106. Habitus, left lateral view of Rhyncomya pruinosa male BMSA DIP 16807 from South Africa; scale bar = 2 mm.