Exoprosopa luteicosta Bezzi

Greathead, D. J., 2001, A study of the Exoprosopa busiris (Jaennicke) group of Bezzi (1924) in tropical Africa (Diptera: Bombyliidae), Journal of Natural History 35 (1), pp. 127-147 : 133-135

Exoprosopa luteicosta Bezzi

(Figures 2, 9, 15)

Exoprosopa luteicosta Bezzi 1921: 161 , Namibia

Exoprosopa albonigra Bezzi, 1924: 349 , Malawi [examined] syn. n.

Exoprosopa saskae SzilaÂdy, 1942: 100 , Tanzania syn. n.

Hesse (1956) based his interpretation of E. luteicosta on the ®rst specimen (from Ovamboland, Namibia) listed by Bezzi (1921) and described a variety of E. luteicosta, var. metapleuralis , which has extensive black hair on the pleura and more extensive black hair at the sides of the abdomen. Further, he described the specimen from Touws River (W. Cape) listed by Bezzi (1921) as doubtfully E. luteicosta as a new species, E. majuscula , and a further three species barnardi, atrisquama and brachipleuralis, all from single specimens.

Specimens standing under E. luteicosta in the Natural History Museum include a specimen from Namibia identi®ed by Hesse. Comparison of this material with the type series of E. albonigra Bezzi indicates that they are conspeci®c. Examination of the male genitalia of specimens in my collection from East Africa shows no diOEerences from the illustration of the male genitalia of E. luteicosta given by Hesse (1956). Therefore, I conclude that E. albonigra Bezzi is a synonym of E. luteicosta Bezzi. It is a variable species in size, the intensity of the infuscation of the wing, extent of black hair on the thorax and sides of the abdomen and of black hair and scales on the posterior abdominal sterna, presence of some pale whitish scales on the femora among the black ones and colour of the legs which varies from almost black to red±brown. A band of white scales is also faintly indicated on the ®fth tergum in some specimens. However, the margins of the veins are never infuscated, as in E. atrinasis , E. goliath , E. brevinasis and E. magnipennis . The wings are not distinctly longer than the body as in the last three nor are the scales on the legs ochreous as in the last two. Further, although there is a tendency to reddening of the cuticle on the face, pleura and sides of the abdomen, the antennae are never red as in E. magnipennis . Some specimens in the Natural History Museum have been labelled as E. eluta Loew , described from`CaOEraria’, but this is clearly incorrect because, although E. eluta has a similar coloration and body pattern, it has a clear cut dimidiate wing infuscation and is considerably smaller on average (8±13.5 mm). Given the variability of E. luteicosta the similar species described by Hesse (1956) and noted above require critical examination to determine their status.

SzilaÂdy (1942) described E. saskae from Dar-es-Salaam. The description ®ts with E. luteicosta but its identity cannot be checked as the specimens in the Hungarian Museum were destroyed, however, I am su ciently con®dent that I have designated it a synonym.

As interpreted here E. luteicosta is the most widespread and variable of the series. Full descriptions were published by Bezzi (1921) and Hesse (1956) who also illustrated the male genitalia.

Diagnosis

Head black, lower part of frons and genae brownish±yellow, grey tomentose. Hair on frons and upper part of facial cone black and with ®ne gold scales; at sides of antennae, genae and sides of facial cone glistening yellow to silvery. Occiput with short decumbent gold hair above and silvery scales at sides. Antennae black with black hair. First ¯agellomere elongate conical, second, 2±3 times as long as wide, style minute. Proboscis black, labella projecting. Thorax black, calli reddened, scutellum red. Macrochetae and short hair on mesonotum black. Longer hair on margins of mesonotum ochreous. Pleura with yellowish±white hair and a patch of white scales on sternopleuron. A few black bristly hairs on coxae. Mesonotum and scutellum with short adpressed brownish±yellow and black scales. Legs dark red with dense black scales and macrochetae, thus appearing black. A complete row of macrochetae on underside of f3 and 3±4 anteroventral and posteroventral on f 2; tibiae smooth, as long as f 1; tarsi ÷ length of t1. Claws black, reddish at bases. Abdomen black, t1 with whitish hair: t2 anterior half white, rest black; t3 white at sides and indistinctly so in middle; t4 white on anterior ö±½; t5 black; t6±t7 white. Hair at sides and apex black. Sterna 1±4 white, remainder black with a scattering of white scales. Wing (®gure 2) with veins brown, base, costal cell and br infuscated brown, gradually fading to hyaline in radial sector. More or less distinct brown spots on bifurcation of R, r±m, m±m and m±cu. Basal comb and hook black. 2+3

Squama brown, fringe white. Haltere blackish. Male genitalia (®gure 9) robust and with a long tongue-shaped epiphallus. Spermatheca (®gure 15) with a small spherical bulb, long narrow tubular middle section and globular thin-walled basal section. Length of body, 10±16 mm; of wing 11±17 mm.

Material examined

Angola: Mt. Lubiri , 6 miles NW Alto Hama, 1 1 l m, 7.iii.1972 (labelled as E.

? luteicosta by J. Bowden) ( BMNH). Botswana: Bakgatla , Sebele, 1 1 l m, 21.xii.1968 , W. R. Ingram ( DJG); Lake Ngami , 1m, Andersson ( BMNH). Ethiopia: Arussi Country, Gambogi, 1, l 19.x.1908 , R.E. Drake Brockman ( BMNH). Kenya: Shimba Hills , 2, l 14.i.1983 , R. H. Markham ( DJG); Shimba Hills , game reserve, 1, l 1.x.1966 , D. J. Greathead ( DJG); Shimba Hills , forest, 1, l 11.vi.1973 , D. J.

Greathead ( DJG) ; Shimba Hills , Mombasa, 1000 ft, 1m, 6.vi.1912, N. J. Radford ( BMNH) ; coast W of Tiwi , 1 7 l m, 13.v.1963, D. J. Greathead ( DJG) ; Coast , Magagoni, 2m, 18.vi.1962, D. J. Greathead ( DJG) ; same, 2 2 l m, 14.v.1963; Coast, Diani , 1m, 11.v.1963, D. J. Greathead ( DJG) ; Cha Simba Bridge , 1, l 14.v.1963, D. J. Greathead ( DJG) ; Lugh , 1, l 2.xi.1911, G. R. H. Chell (listed under E.

brevinasis by Bezzi, 1924) ( BMNH). Malawi: Fort Johnston, 1m, i.1910, H. N. Tata ( BMNH); Ruo, 1, l[1933], R. C. Wood ( BMNH) (labelled as E. eluta ); SW shore Lake Nyasa, Fort Johnston±Monkey Island, 1850 ft, 1, l25.ii± 4.iii.1910, S. A. Neave ( BMNH). Mozambique: V. Bocage, 1 2 l m, 25.xi.1916, R. C. Wood ( BMNH) (labelled as E. eluta by Bryant); Port Amelia, 1m, 1914, F. V. Boste ( BMNH); E of Mt. Mlange, 1m, 28.xi.1913, S. A. Neave ( BMNH). Namibia: Kaross, 1 l(labelled as E. luteicosta by A. J. Hesse) ( BMNH); Otjitambi Farm, 27 miles ESE Kamanjab, 1 2 l m, 13± 15.ii.1972 (labelled as E. luteicosta by J. Bowden) ( BMNH); Kalm River, 5 miles N Usakos, 1m, 30± 31.i.1972 ( BMNH). Somalia: Baidoa, 1m, 7.xi.1953, Desert Locust Survey ( DJG); 10 miles S of El Afwein, 1, l 30.x.1961, C. F. Hemming ( DJG). South Africa: Gauteng [Transvaal], Pretoria, 1m, 1910, W. L. Distant ( BMNH); same 1 2 l m, 1911, W. L. Distant ( BMNH); same, 1m, 25.xii.1912, H. K.

Munro ( BMNH) ; same, 2 1 l m, 20.iii.1914, J. Brincker ( BMNH) ; same, 1, l 21.xii.1914 ( BMNH) ; Waterkloof , 1, l1911, W. L. Distant ( BMNH) . Tanzania: Rukwa, Kafukola , 1, l 8.xii.1953, R. F. Chapman ( DJG) ; Moshi, Lyamungu , 1, l 5.v.1967, I. A. D. Robertson ( DJG) ; SW Sagalla Swamp , 1m, 28.x.1947 ( BMNH) . Uganda: Karamoja, nr. Toror Mt. , 1m, 12 iv.1969, D. J. Greathead ( DJG) ; Karamoja, Mt. Kadam , 1, l 1.v.1950, van Someren ( BMNH) . Zambia: Feira Dist. , 1m, 1911, E. A. Colman ( BMNH) . Zimbabwe: Que Que , 2, l 5.xii.1959, D. and A. Greathead ( DJG) .

Distribution

Angola, Botswana, Ethiopia, Kenya, Malawi, Mozambique, Namibia, Somalia, South Africa (Gauteng, KwaZulu±Natal), Tanzania, Uganda, Zambia, Zimbabwe (®gure 18).