NATURAL HISTORY OF SOUTH AFRICA 



their way into the victim's blood, where they multiply 

 rapidly. The mosquitoes have many natural enemies. 

 The wrigglers are preyed on by small fish, the larvae of 

 dragon flies, water beetles, and other aquatic creatures. 

 Authorities on mosquitoes and mosquito-borne 

 diseases, in mentioning the natural enemies of mos- 

 quitoes, either omit to mention birds or speak of them 

 as being of no practical value as mosquito destroyers. 

 On the contrary, birds feed greedily on adult mosqui- 

 toes. All species of swallows, martins, and swifts 

 prey upon them on the wing when they begin to fly 

 at sundown. The night jar feeds upon them all 

 night. The warblers, of which there are a large 

 number of species, search them out in their lurking 

 places during daylight hours, and dispose of vast 

 numbers. Many species of fly-catchers join forces 

 with the swallows in capturing these pests on the 

 wing, and continue their onslaught until it is too 

 dark for them to see. 



APHIDES, OR PLANT LICE 



These small insects live on the juices of plants, 

 the skin of which they pierce preparatory to sucking 

 out the juices. They may be seen clustered on the 

 buds and tender shoots. Warblers and other small 

 birds feed freely on these pests. They also utilise 

 them as food for their nestlings. 



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