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infected mosquito, it follows that there are three main lines of 

 action which may be taken in preventing the spread of the disease : 

 (1) The parasite itself may be attacked in the blood of infected 

 persons, (2) Measures may be taken to prevent mosquitoes biting 

 such persons and so becoming infected, (3) Attempts may be made 

 to exterminate or reduce in numbers the mosquitoes which, once 

 infected, are capable of passing on the disease to healthy people. 



In this country, owing to the comparatively small number of 

 malaria patients, the most effective lines to follow are undoubtedly 

 the first two. Steps may be taken to identify and treat medically 

 all who recently had malaria fever, and as far as possible to 

 ensure that as long as they are harbouring parasites in their 

 blood they are not bitten by mosquitoes. It is satisfactory to 

 know that both the Army and civil medical authorities are alive 

 to the necessity of taking action along these lines. There 

 remains, however, the third method of malaria prevention by 

 mosquito control. While there may not be any present necessit) 

 to undertake any large scale campaign of mosquito extermina- 

 tion it is certainly desirable to take some steps towards* reducing 

 the numbers of these noxious insects in the districts where tb> 

 are most abundant. Moreover, whatever anyone can do in this 

 direction in any locality will help to minimise the danger of infec- 

 tion. To this end a knowledge of our native mosquitoes and their 

 habits and life histories is essential. 



Of the eighteen species of mosquitoes occuring in this country, 

 three belong to the genus Anopheles, which includes all the malaria 

 carriers. The remainder, chiefly woodland and salt marsh pests, 

 are harmless from the point of disease carriage, though often 

 annoying enough through their biting habits. 



The three potential malaria carriers require different methods 

 of attack on account of their different life histories which are 

 briefly as follows : — 



1. Anopheles plumb eus is not at all uncommon in 

 wooded districts throughout the spring, summer and autumn, 

 biting freely, and sometimes though not habitually entering 

 houses. Its early stages are passed in the water which col- 

 lects in holes in beech and other trees, either in the branches 

 or at the roots. The simplest and most efficient method of 

 attack is to fill up all such hollows and so obliterate the insects' 

 possible breeding places; this should be done by preference in 

 the winter, when there are no adult flies and when the water- 

 carying holes can be most easily discovered. 



2. Anopheles bifurcatus is a very abundant species in 

 marshy country and the neighbourhood of rivers and streams. 

 It bites out of doors, chiefly at dusk, but seldom enters houses, 

 and on this account may not be a serious danger. The flies 

 themselves do not survive the winter, but the larvae occur all 

 through the year in stagnant or slowly moving water, chiefly 



