44 Mites Injurious to Domestic Animals. 



They consider the Psoroptes living in the ear to be a new species 

 which they describe under the name P. hippotis. Only two of the 

 longer hairs on the posterior abdominal lobes of the male of P. 

 hippotis have their bases contiguous, whereas in P. communis, var. 

 equi, three of these hairs originate quite close together, the bases 

 of all three being contiguous and on the same level. It seems possible 

 to the author that P. hippotis may prove to be identical with P. 

 communis, var. cuniculi, or P. c., var. ovis, both of which have the 

 hairs on the posterior abdominal lobes of the male disposed in a 

 similar way (see text-fig. 3, b and c). Professor A. Henry states that 



r 



FIG. 26. 



(a) Posterior end of nymph of Pterolichus bicaudatus (p. 64), from 



above, showing shape of dorsal shield, (b) Posterior end of nymph 



of Pterolichus sculpturatus (p. 64). (Original). 



otocariasis due to Psoroptes is very common in the horse, sometimes 

 being present in 70 per cent, of the horses examined in France. 



At the beginning of the great war all but a very small percentage 

 of the cases of mange were due to Psoroptes, but this complaint 

 became quite rare later, and sarcoptic mange became prevalent. 



Infection is spread through contact between diseased animals 

 and also through contaminated harness, grooming implements, 

 rugs, stable utensils, litter, etc. Anything that has come in contact 

 with an animal suffering from mange may remain infectious for 

 several weeks ; hence the need for cleanliness and disinfection 

 with cresyl or other suitable preparation. 



Both sarcoptic and psoroptic mange should be notified to an 

 inspector (in the London district) or to a police constable (rural districts). 



