NATURAL HISTORY OF SOUTH AFRICA 



way is of little value. Hundreds of species of birds 

 feed upon locusts and grasshoppers, and if it were not 

 for our feathered allies these pests would make stock 

 rearing and agriculture impossible. 



Guinea-fowls, partridges, and pheasants dig up 

 the locust eggs and feed on them. 



TICKS 



There are a large number of species of ticks (Acari). 

 They are parasitic on animals, and feed on their blood. 

 All ticks pass through the following stages : — 



i. The egg. 



2. The larva. 



3. The nymph. 



4. The adult. 



The adult female, gorged with the blood of her 

 host, drops to the ground and, crawling into a tuft of 

 grass, a crevice, under leaves, etc., deposits a large 

 coherent mass of eggs, and soon afterwards dies. The 

 number of eggs laid by a single tick varies from about 

 2,000 to 18,000, according to the species. The larvae 

 have six legs. They crawl up the stems of grasses 

 and other plants and gather at the top in clusters, and 

 wait for an animal to brush past. They cling to the 

 hair of its legs and body, and fasten upon the skin 

 and feed. After distending themselves with blood, 

 they moult and change into nymphs with eight legs. 



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