CHAPTER I 



Introduction 



THE Acarina are to be found in almost every habitat available to 

 animal life. Careful examination of the nearest handful of soil 

 will surely uncover several (Figure 1), and in many localities literally 

 thousands of specimens will be found. The feathers of birds are fre- 

 quently alive with mites as are the pelts of animals. Many people carry 

 a colony of follicle mites in their facial pores. Fresh water streams, 

 lakes, and ponds have their mite faunas. The oceans are not free from 

 them. Some mites are adapted to live in the hot water of springs that 

 occur in certain volcanic regions. Insects, whatever their habitat, act 

 as hosts for many species. Mites invade the internal organs of man and 

 animals, both vertebrate and invertebrate. Most plants produce suit- 

 able quarters, and examination of the debris from the fork of any tree 

 will yield specimens. This world of life remains unknown to most men. 

 Some zoologists and even some entomologists have never seen mites in 

 their native haunts. Few of them appreciate the wealth of species that 

 are at hand everywhere. 



Some of the Acarina, however, are known to the layman, and others 

 frequently call attention to themselves by their activities. Ticks are well 

 known to most people of the world because they are large enough to 

 be seen readily with the naked eye and because frequently they attack 

 man and his domestic animals. In the southern United States most 

 people have had the misfortune to make the acquaintance of chiggers 

 although few of them would recognize one as the larva of a mite. Fruit 

 growers know the spider mites at first hand, and the eriophyids, an- 

 other group of mites, are familiar to them. Many dog owners owe their 

 introduction to the Acarina to mange-producing mites that attack their 

 pets. People who work with stored food products, such as grain or 

 copra, are at times aware of some of the mites that infest these prod- 



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