ARACHNIDS, CENTIPEDES, AND MILLIPEDES— ARTHROPODS 205 



sulfur soap and ointments will usually terminate the infection in a short 

 time. 



The mange of cats and dogs and other domestic animals is caused by 

 the mange mites which burrow around in the skin like the itch mites. 



The tiny chiggers or red bugs are mites that may be so abundant in 

 the southern part of the country that a person will look as if he has the 

 measles after walking through grass in the spring or early summer. 

 They attach themselves to the skin and inject a digestive fluid which 

 forms a little burrow through which they feed. This fluid is quite irri- 

 tating to the skin of some persons and causes large, raised red blotches 



<? 9 



Introduction to Parasitology, Chandler, John Wiley & Sons, Inc. 

 Fig. 14.5. Spotted fever tick. 



and an almost unbearable itching. Chandler quotes a descripiton of 

 them which cannot be improved upon. The chigger is a "small thing, 

 but mighty; a torturer — a murderer of sleep ; the tormenter of entomolo- 

 gists, botanists, and others who encroach on its domains ; not that it bites 

 or stings — it does neither; worse than either, it just tickles." 



Plants are by no means exempt from mite infestation. One of the 

 most serious of the plant mites is the red spider. Red spiders are great 

 pests on fruit trees, and evergreens may be killed by a heavy infection 

 of them. Protection may be given by regular use of poisonous sprays 

 that kill the mites. 



The ticks are blood-sucking arachnids that not only cause incon- 

 venience to their hosts, but spread serious diseases. This is possible be- 

 cause their life history involves several hosts. When the young ticks 



