Sarcoptiformes 363 



2. Knemidokoptes Fiirstenburg, 1870 (= our Cnemidocoptes) 

 Type. Sarcoptes mutans Robin and Lanquetin, 1859 



3. NotoedresR^\\\\eX.\?>93> 



TypQ. Sarcoptes cati Hering, 1838 (= Sarcoptes minor var. cati 

 Railliet, 1893) 



4. Nycteridocoptes Oudemans, 1897 



Type. Nycteridocoptes poppei Oudemans, 1897 



5. Prosopodectes C^nQ^ix'mi, 1897 



Type. Sarcoptes chiropteralis Trouessart, 1896 



6. Teincoptes Rodheim, 1923 



Type. Teinocoptes epomorphi Rodheim, 1923 



7. Trixacarus Sellnick, 1944 



Type. Trixacarus diversus Sellnick, 1944 



Discussion: The Sarcoptes scabiei of man and other animals such as 

 dogs, cattle, pigs, sheep, goats, camels, rabbits, and horses are mor- 

 phologically alike but probably consist of biological races. The spe- 

 cies from horse, for example, can attack man but will not usually 

 produce a permanent infestation. 



Mellanby 1943 has presented an excellent review of the scabies 

 mite in England from which most of the following account is taken. ^ 

 The life cycle is very simple, consisting of egg, larva, nymph, male 

 adult, immature, and mature female. The transformation of the im- 

 mature female to the ovigerous female probably takes place after fer- 

 tilization. A new victim is successfully infected in all probability by 

 newly fertilized females which can move rapidly on warm skin. The 

 mite takes about one hour tO bury itself into the homy layer of skin 

 and goes no deeper. The burrowing is accomplished by the suckers 

 adhering to the skin and the legs and mouth parts cutting into the 

 host. The mature female usually stays in the burrow her entire life. 

 She may remain in the burrow for three weeks and then leave, appar- 

 ently of her own accord. The mite begins egg-laying within a few 

 hours after starting her burrow, laying eggs at two- to three-day in- 

 tervals for about two months, stringing the eggs out behind her as she 

 lengthens her burrow. In the thick, horny layer the mite does not raise 

 a lump but in the thinner skin the mite raises a tiny lump. Eggs may 

 hatch in three to eight days at 35° C, although usually it takes about 

 five days. The larvae leave the burrows and move about on the skin 

 looking for shelter and probably food. Larvae and nymphs are to be 



1 1 am indebted to G. W. Eddy for reviewing this section and adding his own obser- 

 vations made on "self-infection" with gravid female mites. 



