916 CYCLOPEDIA OF LIVE STOCK AND COMPLETE STOCK DOCTOR. 



carried on the legs. In the male they are seen on the four pairs of legs ; 

 in the female, upon the first, second, ,and fourth pairs only. In their 

 immature form the Psoroptes or common mange mites have three pairs of 

 legs, while in the adult state they possess four. The latter with five joints 

 are fitted with suction cups covered with fine hair and armed with claws or 

 hooks. The head, thorax, and abdomen are not separated. The mouth 

 parts are represented by mandibles or jaws. The skin surface is covered 

 with scales, hair, spikes, or silky hair, etc. 



Females, which are larger than males, lay from 20 to 24 eggs; at the 

 end of 4 to 7 days the larvse come out and, after having undergone 3 or 

 4 changes, arrive at the stage of reproduction from the fourteenth to the 

 seventeenth day. If exposed to damp air, or placed upon wet manure, the 

 mange mites continue to live from 6 to 8 weeks. Upon damp ground the 

 eggs remain alive from 2 to 4 weeks. In a dry place they lose their 

 vitality after 4 to 6 days. Moderate heat is favorable to their vitality and 

 to the hatching of the mites. 



In warm places under cover, and during the summer, their move- 

 ments are more active and they multiply more rapidly than under the 

 opposite condition. It has been estimated that one female alone may 

 produce 1,500,000 individuals in 90 days. 



Each animal species has its specific mange parasites, or mites; conse- 

 quently the expression "mange" must necessarily be incomplete unless 

 the variety of the parasite is indicated. Thus, of the Psoroptic variety, 

 we have the ox mange mites, the horse mange mites, and the sheep mange 

 mites. 



In each of these animals we also have the Symbiotic, or tail mange, 

 and in each the variety would be designated as in the case of the Pso- 

 roptic or common form; but in neither variety is the contagion trans- 

 mitted from one species of animal to the other. The tail-mange mites 

 live especially upon the surface of the skin of the extremities, and exist in 

 scabs in the outer layer of the skin. Their outlines are visible to the 

 naked eye. The head is short and wider than it is long. The body is 

 slightly egg-shaped and notched upon the outer edge. The legs are long 

 and the sucking cups are shaped like a Roman shield, and are distributed 

 in both the male and female, as in the case of the same organs on the legs 

 of the common mange mites. 



Sarcoptic mange is a more serious disease than either of those already 

 described, but is not common to cattle. It would not, therefore, seem im- 

 portant to refer to this form of mange parasite and occupy space in this 

 bulletin except by a reference to the serious disease which is produced by 

 this variety of mite through certain characteristics natural to it. We find 

 Sarcoptic mange in the following dornesticated animals: Horse, sheep, 

 goat, dog, cat and pig. 



