58,i 
A  PRELIMINARY  NOTE  ON  THE 
PREVALENCE  OE  MOSQUITOES 
IN  CAIRO  AND  ITS  ENVIRONS 
BY 
F.  C.  WILLCOCKS, 
[■NTOMOLOGIST  TO  THE  KHEDEVIAL  AGRICULTURAL  SOCIETY 
( Recejved  for  publication  i^th  February^  K^io.J 
The  Nile  Floods  of  igo8  and  1909  were  exceptionally  high  as 
compared  with  those  of  the  previous  three  years.  In  igo8  the 
maximum  level  reached  at  Rhoda  Bridge  was  19' 82  metres  ;  this  year 
(1909)  the  level  was  slightly  less,  viz.,  19-69  metres.  The  average 
maximum  heights  for  the  years  ending  1905-190;  was  about  18-20 
metres. 
One  of  the  results  of  such  high  Niles  during  the  past  two  seasons 
has  been  to  flood,  by  infiltration  through  the  soil,  the  low-lying  parts 
of  Cairo  and  its  environs.  In  many  of  these  collections  of  infiltration 
water,  mosquitoes  breed  in  large  numbers  ;  the  species  varying  to 
some  extent  with  the  kind  of  breeding-place.  F'ortunately,  in  the 
majority  of  cases  the  infiltration  breeding-places  are,  but  temporary, 
persisting  from  two  to  three  months  only. 
The  breeding-places  of  this  nature  in  Cairo  and  its  environs  are 
as  follows 
-< 
•excavated. 
Cairo. 
A.  Flooded  building-sites  . 
Xmexcavated. 
H.  Flooded  basementsjof  buildings  (cellars)* 
II. 
C.  Flooded  gardens. 
D.  Disused  sakia  pits  (water-wheel  pits)  in  gardens. 
Environs  of  Cairo. 
E.  Borrow-pits  alongside  roadway  and  railway  embankments, 
F.  Flooded  garden  and  agricultural  land. 
G.  Sakia  pits — not  in  use. 
■’■Obaersalinn  by  J)f,  EL  H.  Ross,  Public  Health  Department. 
