265 



NOTES ON THE ANOPHELES IN CEYLON AND 



ON THE LIFE HISTORY OF ANOPHELES 



FULIGINOSUS. GILES. 



By 



Majok N. Manders, r.a.m.c, f.e.s. 



( With Remarks and Drawings — Plates A and B — by E. E. Green, 

 F.E.S.) Entomologist to the Government of Ceylon.) 



Many of these notes will be found identical with those of Dr. Sambon 

 when studying the life history of Anopheles maculipennis, (Meign), 

 British Medical Journal, January 26th, 1801, but it will probably be 

 found necessary to study completely each species of the genus in our 

 attempts to unravel many still obscure matters connected with mosquitoes 

 and malaria ; hence these notes taken at Trincomalie, extending from 

 November 1900 to June 1901. 



Anopheles, in my experience, can be more readily collected in the 

 larval than in any other stage. The general appearance of the larva is 

 now well known. If you find an insect (in appearance like fig. 1 of 

 the plate) which, when alarmed, wriggles head first to the bottom of a 

 glass, and after remaining there for a minute or two wriggles tail first 

 to the surface ; which on the surface progresses tail first in a skating 

 manner and which finally rests with its tail against the side with its 

 head pointing to the centre, you may be pretty certain you have obtain- 

 ed some member of the genus Anopheles. 



I find that, in order to discover the larvae of Anopheles, the following 

 principles must be borne in mind : — 



1. A certain amount of the food plant must be present. 



2. The water must be tolerably clear ; I have never found them 



in muddy water. This is directly contrary to some observ- 

 ers : see " The Campaign Against Ague," by Herbert Dur- 

 ham, F.R.C.S., British Medical Journal, March 2nd, 1901, 

 who writes : " In fact, all the pools in which I have met 

 "Anopheles' larvas here (para. 1) have been muddy and 

 " without manifest green growth." 



3. If the food plant is so abundant as to form a thick scum over 



the entire surface of the water, Anopheles is absent. 



4. It is absent as a rule in temporary collections of water such as 



puddles of rain water, unless the food plant is present, 

 which is unlikely. Culex can be found anywhere, and is 

 altogether a more robust creature than Anopheles. 



