326 



W. B. JOHNSON. 



1. High percentage of Anopheles obtained. 



The percentage of Anopheles to total mosquitos caught was 88-7 (83-4 per cent., 

 996 per cent., 757 per cent., 89*5 per cent.). Even if Katagum (Table II) be 

 excluded— the station being exceptional owing to the marshy nature of the country — 

 the percentage is still high, viz., 82-9 per cent. 



2. Preponderance of certain species of Anopheles. 



In all, 10 species of Anopheles were obtained (including one new species). A. eostalis 

 and A. funestus show an overwhelming preponderance, forming 92-9 per cent, of 

 all the Anopheles obtained. 



Table I 

 Kaduna. 



Table II 

 Katagum. 



Table III 

 Zungeru. 



Table IV 

 Zungeru. 



Combined 

 tables. 



A. eostalis 



A. funestus 



Other species of Anoj)heles 



81-1% 



16-6% 



2-3% 



66-5% 

 8-4% 



42-6% 

 38-6% 

 18-8% 



61-7% 

 23-0% 

 15-3% 



7-1 ° 



If A. rufipes is included with A. eostalis and A. funestus these three species form 

 984 per cent, of all the Anopheles obtained : — 



Table I 

 Kaduna. 



Table II 

 Katagum. 



Table III 

 Zungeru. 



Table IV 

 Zungeru. 



Combined 

 tables. 



A. eostalis, A. funestus and 



A. rufipes 

 Other species of Anopheles 



98-7% 

 1-3% 



98-8% 



96-5% 

 3-5% 



96'5% 

 3-5% 



98-4% 

 '■6% 



This high proportion of A. eostalis and A. funestus as domestic pests appears 

 to hold good all over the country. As a further example I may quote the following — 

 a short experience at Ibi station on the river Benue compared with two journeys 

 upon the same river by steamer : — 





A. eostalis and 

 A . funestus 

 (combined). 



Other 



Anopheles. 



Other 

 Mosquitos. 



%of 



A. eostalis and 



A. funestus 



to total 

 Anopheles. 



At Ibi station : — ■ 

 3 weeks in Aug., 

 1918 .. 



249 



2 



4 



99-2% 



On boat on R. Benue 

 29 days. Sept. 1917 

 and July 1918 . . 



180 



105* 



82 



63-1% 



* A. welteomei and A. nili. 



