COUNT THE MALE MOSQUITOS 97 



Several kinds of mosquito traps have been devised, 

 but they give little exact information. For every ten 

 mosquitos caught in a trap there are probably hun- 

 dreds that avoid capture. The writer has tried 

 many experiments with traps, but has been obliged 

 to give them up. There is one simple way by which 

 a rough estimate of mosquito reduction can be 

 obtained. It has been stated before that the first 

 mosquitos to be reduced will be the males. Male 

 mosquitos habitually remain for their short lives near 

 the breeding-place where they themselves were born. 

 Only occasionally does a male follow the females into 

 houses ; the large proportion remain near the water 

 to fertilise the females as they emerge from the pupa. 

 But in a room infested with female mosquitos an 

 occasional male will find his way there to fertilise a 

 possible virgin female that has wandered with her 

 sisters into the house. These males can be counted 

 before the anti-mosquito measures start, and counted 

 again a month after. Choose several houses in 

 scattered parts of the town, and in one of the bed- 

 rooms of each count the number of males found 

 resting on the mosquito curtains. Note the houses 

 and the rooms, and utilise them again for the next 

 count. If there is a reduction of males, the work of 

 mosquito prevention is going on well. Examine the 

 nets in the morning. If after some weeks there are 

 still males to be seen on the nets, it is certain that 

 there are yet breeding-places to be dealt with. If on 

 one mosquito curtain there are several male mos- 

 quitos, it is only necessary to find the breeding-place 

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