176 SANITARY ENTOMOLOGY 



of animals or man occurring in the head sinuses, throat, or occasionally 

 the eye. For example, the sheep hot, Oestrus ovis Linnaeus, and the deer 

 bots, Cephenomyia spp. 



Fifth, BLOOD-SUCKING SPECIES. Higlily specialized fonns with 

 blood sucking as a normal habit, exclusively parasites of man or animals, 

 such as the Congo floor maggot attacking man, and larva? of the genus 

 Protocalliphora attacking birds. 



Myiasis is caused by many species in several families. The habits, 

 in regard to myiasis, of tlie species of any single family vary widely as 

 might be expected in groups which have become more or less specialized. 

 For instance, the family Oestridae, which is the only family having all its 

 species concerned in myiasis, has members which infest the stomach, others 

 which develop in the nasal passages and still others which produce 

 cutaneous myiasis. The family Muscidae also exhibits very diverse habits 

 in this regard, some members being concerned in destructive myiasis, 

 others in specialized dermal cases and still others are blood suckers. 



Myiasis in animals is not generally considered in connection with 

 human cases. There exists, however, a ver}'^ intimate interrelationship; 

 in fact, the prevention of myiasis in man is largely dependent upon the 

 control of the trouble in animals. Entomologists- engaged in sanitary 

 work must be prepared to handle insect attack on animals as well as on 

 man. 



Owing to the need for careful determination of the exact species con- 

 cerned in cases of myiasis, both for the immediate needs of the case and for 

 the benefit of science, it is highly desirable tliat the larva? concerned be 

 bred to adults whenever possible. Specific determination of tlie lai'vae, 

 especially when small, is, to say the least, very difficult, but a few should 

 be preserved in alcohol for record and future identification when larval 

 characters are better understood. Some suggestions as to breeding 

 methods are apropos. There is no use endeavoring to rear Oestrids after 

 extraction unless well matured. Most of the larv^T from wounds will 

 usually develop on beef. Care must be exercised in rearing the flies to 

 avoid infestation of the material by other species, especially Sarcophagids 

 which will drop larva? throvigh screen wire onto meat or excrement. A 

 double cage is best to- avoid this ; one of these should have a solid top. 

 Good ventilation is important and sand slightly moist but not wet should 

 be provided beneath the meat. The meat may be partially buried to 

 retain moisture and reduce odor. It should be remembered that the 

 larvje have a strong tendency to migrate when ready to pupate. 



TISSUE-DESTROYING FORMS 



It should be said that most forms of lai-i'ae attacking man or animals 

 may destro}^ body cells to some extent but not in the sense of the rapid 



