Mosquitoes and Malarial Fever 515 



reference to the mosquitoes most concerned — the anopheles — which 

 fly but short distances. By closing all the domestic cisterns and 

 reservoirs, cesspools, etc., so that no mosquitoes can get in to breed 

 or get out to bite, and by draining the pools for half a mile in all 

 directions from human habitations, the number of anopheles mos- 

 quitoes can be made almost negligible. If at the same time no 

 mosquitoes are any longer permitted to infect themselves by biting 

 infected human beings, the spread of the disease must be greatly 

 restricted or checked. 



Mosquitoes and Malarial Fever 



In order that the student may be able to differentiate with 

 reasonable accuracy such mosquitoes as come under his observation, 

 use must be made of tabulations, to correctly use which, however, 

 the student should have some familiarity with insect structure and 

 the general principles of entomology. The best works of reference 

 for this purpose, that have come under observation to the present 

 time are "A Text-book of Medical Entomology" by Pat ton and 

 Cragg, published by the Christian Literature Society for India, 

 London, Madras and Calcutta, 1913, and the "Handbook of Medical 

 Entomology" by Riley and Johannsen, the Comstock Publishing 

 Co., Ithaca, New York, 19x5. 



The mosquitoes comprise a family of dipterous or two-winged 

 insects, included in the family Culicidae. They can be recognized, 

 first by their weU-known general form, and second by the presence 

 of scales upon some part of the head, thorax, abdomen, and wings. 

 For the rough and ready identification of the larger groups and 

 principal genera, the following table compiled from various authors 

 may answer. For more precise information and for the identi- 

 fication of the species, of which hundreds are now described, refer- 

 ence must be made to the large works recommended above. 



CLASSIFICATION (Stitt) 



There are four subfamilies of CULICID-iE, differentiated according to the 

 palpi: 



I. Palpi as long or longer than the proboscis in the male. 



1. Palpi as long as the proboscis in the female; 



proboscis straight Anophelin^. 



2. Palpi as long or shorter than the proboscis; 



proboscis curved Megarehinin^ 



3. Palpi shorter than the proboscis CuliciN/E. 



II. Palpi shorter than the proboscis in the male and 



female ^din^. 



Of these the Anophelinae is the one family concerned in the transmission of 

 malarial fever, so that it is important to be able to differentiate the genera in- 

 cluded in the family. 



Anophelin^ 



I. Scales on head only; hairs on thorax and abdomen. 

 I. Scales on wings large and lanceolate. Palpi only 



slightly scaled Anopheles. 



