﻿294 S. A. NEAVE — NOTES ON THE BLOOD- SUCKING 



flies laying their eggs on the grasses and reeds at the water's edge. The females 

 were very abundant, the few males seen on this occasion being taken on some 

 small trees about 100 yards from the water. The Q eye is black ; the $ eye 

 black below and silvery grey above. 



Tabanus grandissimus, Eic. 



This species is only represented in my collection by two Q Q from the 

 Kalungwisi Valley, Northern Rhodesia, taken in September 1908. It seems to 

 be not uncommon in places on the west shore of Lake Nyasa. 



Tabanus secedens, Walk. 



This is a common fly in Uganda and the Upper Nile Valley, especially in 

 the neighbourhood of forests. The female eye is dark purplish. 



Tabanus socialis, Walk. 



A small series of this characteristically West African species was taken in 

 the Tero Forest, South-East Buddu, Uganda, in September 1911. It was not 

 met with elsewhere. The female eye is dark purplish. 



Tabanus taeniola, P. de B., and var. variatus, Walk. 



This is the most abundant and widely distributed species of the genus in 

 Eastern Africa, especially on the lower ground. In all, about 700 males and 

 670 females were taken of this species and its variety during the tour. In 

 Eastern Africa the var. variatus very much out-numbers the typical form. It 

 would appear, however, that on Mombasa Island, judging from specimens 

 collected by Dr. Haran and Dr. W. J. Radford, and at Voi, typical taeniola is 

 the common form, but this is quite exceptional for East Africa as a whole. 



The eyes of T. taeniola and those of the many other species belonging to this 

 group are all very similar. The female eye is usually of a dull purplish colour. 

 In the male eye this colour is replaced in the upper large-facetted portion by a 

 pale greyish ground with a median dusky band. This band varies in width to 

 some extent even in individuals and is occasionally evanescent. In typical 

 specimens it is narrow, though somewhat broader at the junction of the eyes than 

 at the ends. In species such as T. nyasae, Ric, and T. ustus, Walk., this 

 character is much more pronounced, the band being very broad in the middle 

 and shaped somewhat like an elongate lozenge. 



Tabanus ustus, Walk. 



This insect is a common one before and during the first rains in Northern 

 Rhodesia, Nyasaland and the southern part of German East Africa. The 

 females sometimes occur in very large numbers after the rains have commenced. 

 Between mid-September and the beginning of November in 1910, 221 males and 

 49 females were collected. The eyes resemble those of T. taeniola. 



Tabanus denshami, Aust. 



Both sexes of this species were taken in the Luangwa Valley, N. Rhodesia, in 

 September. Also a single ? from near Fort Hall, British East Africa, in 

 February. The eyes resemble those of T, taeniola. 



