Common Insect Enemies 113 



known that some species of Culex do transmit blood diseases 

 of birds and animals, and it is not beyond the realm of pos- 

 sibility that some of the baffling diseases of humans might 

 also be transmitted by means of these unwelcome intermedi- 

 aries. Let's not forget that not many years have elapsed 

 since malaria was traced to Anopheles and yellow fever to 

 Aedes, and still fewer years have elapsed since two other 

 tropical diseases, dengue and filariasis, were shown to be 

 mosquito-borne. 



The method of attack that has proved so successful in 

 cutting down the population of malaria- and yellow fever- 

 bearing mosquitoes is still the best: Eliminate their breeding 

 places, or at least treat their breeding places so as to disrupt 

 their normal cycle of propagation. Some mosquitoes lay 

 their eggs on the surface of water; others lay theirs on the 

 ground after the pools have dried out, and the eggs remain 

 there until rain or melting snow refills the pools. The eggs 

 of some mosquitoes hatch within a short time after they are 

 laid; with most species, however, the eggs remain as such over 

 the winter; and in certain other species, it is believed that 

 the eggs may remain on dry ground for as long as several 

 years, waiting for the rain that will enable them to hatch. 



The marshlands along the ocean, the innocent-looking 

 meadow pond, the rain barrel alongside the house, the rain- 

 filled tin cans on your refuse pile, these are the breeding 

 places of mosquitoes. Here they lay their eggs, here the 

 eggs hatch into larvae — those well-known "wigglers" which 

 you have seen many times — here the larvae go through four 

 molts and change into pupae, and here after two or three 

 days, the pupae shed their skins and emerge as full-fledged 

 flying mosquitoes. 



It's very simple, then. Get rid of the water and you 



