SIMULIIDAE OF AFRICA 93 



ecological preferences in common with dentulosum and its allies (comprising the 

 subgenus Anasolen in the present treatment) but differing from these and other 

 Simulium by several characters that make their recognition as a separate subgenus 

 desirable for a balanced classification. 



The most notable character of the subgenus Freemanellum is the presence of 

 conspicuous hairing on either side of the katepisternal region of the adult thorax ; 

 in all other subgenera of Ethiopian Simulium, and in most other world Simulium, 

 the katepisternum is bare. Apart from the occasional presence of katepisternal 

 scaling in attreum-group and latipes-group species of Eusimulium, the only other 

 subgenera in which the katepisternum is haired are Gomphostilbia from the Oriental 

 Region and Japan, and Morops from New Guinea and Australia, but both of these 

 subgenera belong clearly among the more primitive forms of' Simulium near to 

 Eusimulium and have no close phyletic relationship with Freemanellum. It may 

 be noted, though, that Morops and Freemanellum are the only two subgenera among 

 world Simulium in which both the katepisternum and the pleural membrane are 

 haired (except for occasional female specimens of Freemanellum in which the pleural 

 membrane appears to be naturally devoid of hair). 



In the Ethiopian fauna Freemanellum is most nearly related to the subgenus 

 Anasolen, from which it differs (apart from the katepisternal character already 

 mentioned) by large claw-teeth and at least slightly downwardly-produced para- 

 procts in the female, by the long narrow styles in the male, by the pupal gill always 

 with four filaments, and by the larger more produced primary brush and reduced 

 main apical tooth of the larval mandible, and by the much longer larval postgenal 

 cleft. It appears also to be related to the subgenus Xenosimulium sgen. n. from 

 Madagascar, in which the larval mandible shows similar modifications from the norm 

 in the enlargement of the comb-teeth and relative reduction of the apical teeth and 

 in extreme development of the primary brush. 



There are no obvious affinities between Freemanellum and any Holarctic or 

 Oriento-Australasian segregate of Simulium, but there appears to be some relation- 

 ship with certain forms in South America that have a strong resemblance to the 

 Ethiopian Anasolen species. The Neotropical Simulium lahillei Paterson & Shannon, 

 type-species of the subgenus Grenierella Vargas & Diaz Najera, has many characters 

 in common with (and to a large extent intermediate between) those of Freemanellum 

 and A nasolen from the Ethiopian Region : in lahillei the male styles are longer than 

 the coxites, the female paraprocts are enlarged and the larval postgenal cleft is 

 elongate-oval recalling the characters found in Freemanellum , but the female tarsal 

 claw-teeth are very small, there are twelve pointed branches in the pupal gill and the 

 hypostomium of the larva has a straight apical row of small but well formed teeth, 

 these characters being much as in Anasolen. 



The species of Freemanellum are exceptional among African black-flies in having 

 a predominantly reddish brown colour, especially rich on the scutum of the male ; 

 in this feature, too, they resemble 5. {Grenierella) lahillei from South America in 

 which the thorax is distinctly orange to reddish brown. A detailed description of 

 lahillei is given by Wygodzinsky (1949). 



