4 R. W. CROSSKEY 



SYNOPSIS 



A new supraspecific classification is proposed for the Simuliidae of the African Continent and 

 its associated islands, based on a wider study of world forms. Identification keys and diagnoses 

 are given for all supraspecific taxa recognized, and two new genera and six new subgenera are 

 erected : tribal taxa are defined on a world basis. Distribution is shown (with maps) for each 

 genus-group taxon occurring in the whole African area, and a brief summary of the bionomy is 

 included for each subgenus found in the Ethiopian and Malagasy Regions. Comparisons are 

 made between the genus-group taxa occurring in the African area and those in other zoogeo- 

 graphical regions and possible affinities discussed. A summary is given of the proposed classifica- 

 tion in which all known African species are placed, and an alphabetical index-catalogue of all 

 species-group names applying to the Ethiopian and Malagasy Regions is included, which shows 

 the status and whereabouts of all types. 



INTRODUCTION 



In the late 1940's and early 1950's onchocerciasis was found to be a much more 

 widespread and serious human filarial disease than had previously been thought, and 

 intensive entomological work on the known or potential Simuliid vectors of oncho- 

 cerciasis was begun in several parts of Africa. An initial difficulty experienced by 

 workers in the field was the lack of any comprehensive work by which the many 

 Simulium species found in tropical Africa could be readily identified, and it was to 

 remedy this that Freeman & de Meillon (1953) prepared their monograph on the 

 Simuliidae of the Ethiopian Region — which has remained, and will continue to be 

 for many years, the standard treatise on the species of this area, although (apart 

 from brief notes on larvae) it deals only with the adult and pupal stages. Crosskey 

 (i960) on the larvae to a large extent supplements Freeman & de Meillon for this 

 stage. 



It was not germane to the main purpose of Freeman & de Meillon (1953) for them 

 to consider the detailed classification of Simuliidae on a world basis, nor would this 

 have been feasible at the time, since up to then no fully comprehensive works on 

 classification had appeared even for the much better known fauna of the Holarctic 

 Region ; since then, however, a large quantum of comprehensive taxonomic work 

 has been published from which a widely agreed world classification of the Simuliidae 

 is beginning to emerge, and it now seems timely to harmonize the classification of 

 African forms (particularly those from the Ethiopian Region) with that of other 

 zoogeographical regions. To do this, I have put forward in this paper a supra- 

 specific classification of the African Simuliidae that is based on a world review of the 

 family and is intended to carry the work of Freeman & de Meillon (1953) a stage 

 further ; in doing so I have thought it useful to embrace the fauna of Palaearctic 

 Africa and the islands most nearly associated with the African Continent, as well as 

 that of the Ethiopian and Malagasy Regions (the latter is treated as distinct from 

 the Ethiopian Region in accordance with current trends in zoogeography). 



The approach is that of orthodox taxonomy using morphological characters from 

 the adult, pupal and larval stages (the egg is devoid of taxonomic features). Micro- 

 morphological characters of the giant chromosomes of the larval salivary glands, 

 which are supposed to have value in unmasking cryptic species, have been little 



