233 



THE PREVALENCE, DISTRIBUTION AND SIGNIFICANCE OF 



SrEGOMYIA FASCIATA, F. (=CALOP[JS, Mg.), IN WEST 



AFRICA. 



By Sm EUBEKT BOYCE, E.R.S. 



With a deficription of the Mosquito and its nearest African allies hy 

 Robert Newsteab, M.So. 



(Maps.) 



Contents. 

 I. Introduction (p. 233). 

 II. Investigation of breeding places (p. 234). 



III. Steyomyia Surveys (p. 237). 



IV. Some characteristics of the Stegomyia and its larvae (p. 238). 



V. Differential diagnosis of Steyomyia fasciat a, vf\t\\ descriptions of two nearlv 



allied species (p. 240). 

 VI. Characteristics of the e^^ and adult larva of Steyomyia fascintu (p. 243). 

 VII. On the life-cycle and larval habits of the Steyomyia (p. 244). 

 VIII. Viability of the ova after long exposure to dry atmospheric conditions (p. 24G). 

 IX. Distribution of the Steyomyia in Africa (p. 248). 

 X, Destruction of Steyomyia fasciata (p. 256). 

 -* XI. Relationship of the distribution of the Steyomyia to Yellow Fever (p. 261). 



I. Introduction. 



Having taken part as a volunteer in the great yellow fever epidemic of 1905 

 in New Orleans, I was later in the same year sent by the Colonial Office to 

 enquire into yellow fever in British Honduras and the adjacent Central 

 American Republics. 



In 1909 I was sent by the Colonial Office to investigate an outbreak of this 

 disease in Barbados, and when there, I was asked to proceed to the other 

 West Indian Islands, and to British Guiana^ in order to examine their position 

 from the point of view of yellow fever. 



Therefore^ when yellow fever made its appearance on the West Coast of 

 Africa this year, 1910, I again gladly availed myself of the opportunity held 

 out to me by the Colonial Office to proceed there to study the circumstances 

 of the outbreak. 



Knowing from my previous experiences the great importance attached to 

 the presence of Stegomyia fasciata in large numbers in any tropical town, I 

 was astonished to find that in very many large towns on the West Coast this 

 species was much more abundant, according to my experience, than in either 



BULL. ENT. RES. VOL. I. TART 4, DECEMBER I9IO. U 



