SIMULIIDAE OF AFRICA 83 



golden scales laterally. Fore tarsi dilated, the basitarsus about 4 -5 times as long as 



its greatest breadth ...... lumbwanum- group (p. 83) 



- Scutum with golden scales only. Fore tarsi narrow or enlarged, the basitarsus 4-5- 



7 o times as long as its greatest breadth . . . berneri- group (p. 83) 



berneri- group. Fore basitarsus narrow or enlarged, 4-5-7-0 times as long as its greatest 

 width. Postnotum bare. o* hypopygium with one long strong parameral hook on each side, 

 sometimes with additional small hook. Pupal gill with 38-95 filaments (Text-fig. 199). Pupal 

 abdomen with normal Simulium onchotaxy. Cocoon complete, covering pupal thorax and 

 abdomen. Larval head not noticeably convex, cephalic apotome broadest near hind margin or 

 only slightly forward ; cephalic fans when open forming usual hemispherical brush, the rays 

 exceptionally slender and filter apparatus very inconspicuous. Larval antenna about as long as 

 stem of cephalic fan, with four segments. Hypostomium of unique form (as Text-fig. 267). 

 Mandible with main apical tooth very large basally, only one small mandibular serration and 

 comb-teeth very reduced. Thoracic and abdominal cuticle covered with fine colourless hairs, 

 these mostly slightly clubbed apically. Abdominal segmentation unusually well marked. 



This small group contains two little known species that occur as larvae and pupae 

 only on the large mature or almost mature nymphs of unidentified species of Elassone- 

 uria Eaton (Ephemeroptera : Oligoneuriidae). To date, associations between 

 berneri-gvoup species and Elassoneuria mayflies have been recorded only from Ghana, 

 Cameroon Republic, northern Angola, and western Uganda but the distribution is 

 likely to be much more widespread than the existing records suggest, and probably 

 other species of the group remain to be discovered. For some years only S. berneri 

 Freeman was known to occur in phoretic relationship with Elassoneuria, but a 

 second species (S. kumboense) has recently been described by Grenier et al. (1965a) : 

 in the original description kumboense was given the status of a subspecies of berneri, 

 but Germain et al. (1966 : 135, footnote) later suggested that kumboense and berneri 

 are two distinct species. They are here provisionally treated as separate species, 

 though undoubtedly extremely closely allied. Ecological aspects of the association 

 between S.(P.) kumboense and Elassoneuria have recently been discussed by 

 Germain & Grenier (1967). 



Included taxa. Simulium (Phoretomyia) berneri Freeman ; S.(P.) kumboense 

 Grenier, Germain & Mouchet. 



lumbwanum- group. Fore tarsus enlarged, basitarsus about 4-5 times as long as its greatest 

 width. Postnotum bare. Scutum with pattern formed by broad median longitudinal band of 

 black-brown or bronze scales with golden scales on either side. $ abdomen shining and bare 

 except for sparse fine erect hairs on last few segments, thick scales confined to base and sides. 

 (J hypopygium with one long strong hook in each parameral organ. Pupal gill with 25-41 

 filaments (Text-fig. 198). Pupal abdomen unique among Simulium, exceptional onchotaxy 

 with a girdle of 22-24 blunt hooks around each segment from 5-7 and with from 4-7 similar 

 irregular blunt hooks each side on segment 8 (Text-figs. 170 & 173) in addition to the normal 

 row of four hooks each side dorsally on segments 3 and 4 ; also some supernumerary spinous 

 hairs or minute hooklets dorsally on segments 2-4 (Text-fig. 170). Cocoon reduced, covering 

 only pupal abdomen. Larval head not convex, cephalic apotome broadest near hind margin ; 

 cephalic fan when open forming hemispherical brush, the rays exceptionally slender and filter 

 apparatus very difficult to see. Larval antenna colourless and reduced (difficult to see), only 

 about half as long as stem of cephalic fan, first two segments lacking suture between. Hypo- 

 stomium with nine apical teeth (as in normal free-living Simulium) but median and corner teeth 



