194 SANITARY ENTOMOLOGY 



form in this group. The fly deposits living larvae on the nose of the 

 sheep and the young maggots work upward through the nasal passage, 

 later entering the head sinuse§. The maggots are quite spiny and hence 

 must produce much irritation. They appear to subsist upon the mucous 

 secretions of the head cavity. Several months are passed- in the host 

 and the larvae drop out and pupate in protected places on the ground, 

 producing flies a few weeks later. 



I know of no record of the attack of man by this species in the 

 United States, but in other countries it frequently attacks the eyes, 

 nose, mouth, and ears. The fly deposits the larvae so quickly that there 

 is little opportunity to protect one's self. The most serious symptoms 

 develop from infestation of the eye where larvae produce severe conjunc- 

 tivitis and in some cases, if not promptly removed, cause the loss of 

 sight. 



In this country the Cervidae (deer, elk, etc.) are attacked by Oestrids 

 of the genus Cephenomyia (C. pratti Hunter, and C. phobifer Clark). 

 The larvEe of these flies are found in the head passages, pharynx, and 

 even in the lungs. 



Europe. — The sheep head bot has a wide distribution in Europe 

 and is responsible for loss among sheep and infestation of man as above 

 described. 



Probably the most important species in this group is Rhmoestrus 

 pwrpureus Brauer, which is a very common parasite of the horse in 

 Russia, Hungary, and Italy. This form is also responsible for cases 

 of myiasis in the eyes of man, the attack apparently being similar to that 

 of Oestrus ovis. Horses are infested by the flies which deposit larvae 

 in the nose or eyes. They are much annoyed by the deposition of the 

 insect and the larvae give rise to fits and other symptoms, mistaken for 

 strangles, sometimes resulting in death. The species is also known to 

 attack the zebra. Cases of the occurrence of this species in the eyes of 

 man have been reported from Jerusalem, and are not infrequent in 

 southern Russia. 



The reindeer in Europe are subject to the attack of Cephenomyia 

 trompe Linnaeus in a way similar to the infestation of sheep by Oestrus 

 ovii. Nativig reports the finding of as many as 100 larvae in the nasal 

 cavity and larynx of a young reindeer. 



Africa. — In Algiers, especially. Oestrus ovis is very destructive to 

 sheep and many cases have been reported by the Sergents and others of 

 the infestation of man by this species. The horse head bot, Rhinoestrus 

 purpureus, occurs in the Egyptian region. The camels are infested by 

 the Oestrid, Cephalomyia maculata Wiedemann (Cephalopsis titUlator 

 Clark) . Larvae thought to be Rhinoestrus nasalis are common in the head 

 sinuses of cattle in parts of Africa. 



