2/6 OUR INSECT FRIENDS AND FOES 



consequences, the vital importance of our doing 

 all in our power to promote original scientific 

 research and investigation, by which it is alone 

 possible to gain that knowledge which will 

 enable us to cope with those insect foes who are 

 transmitting agents of disease. 



Thanks to the splendid work of the little band 

 of scientific men who are devoting their lives to 

 the study of tropical diseases, we now know 

 how to fight the insect transmitting agents of 

 malaria and yellow fever, and good progress has 

 already been made in many districts in the 

 tropics towards stamping out these two diseases. 



To gain some insight into the life-history of 

 the spot-winged Anopheline mosquito, there is 

 no need for us to journey to the tropics, for it is 

 very similar to that of the mosquitos or gnats 

 which dance over every stagnant pool and water- 

 tub during the summer months in England. The 

 mosquitos belong to the order Diptera, or true 

 flies, a group of insects to which the common 

 House-fly, the Bot-fly, and the Gad-fly, also 

 belong. They are characterized in the adult 

 stage by the possession of only one pair of 

 wings, the posterior pair being reduced to mere 

 club-shaped processes, called halteres or balancers, 

 by a piercing and sucking proboscis ; and by 

 undergoing complete metamorphosis egg, larva, 

 pupa, perfect adult insect. 



The mosquitos, or gnats, all belong to the 

 family Cnlicidce, which is again subdivided into 

 a number of sub-families, based upon certain 

 anatomical peculiarities, therefore it is not 

 surprising to find certain points are common to 



