ENTOMOLOGY

176 SANITARY ENTOMOLOGYof animals or man occurring in the head sinuses, throat, or occasionallythe eye. For example, the she~p bot, Oestrus avis Linnaeus, and the deerbots, Cephe'llomyia spp.Fifth, BLOOD-SUCKING SPECIES. Highly specialized forms withblood sucking as a normal habit, exclusi,·cly parasites of mnn or animals,such as the Congo floor maggot attacking man, and larvre of the genusProtocalliphora attacking birds.Myiasis is caused by many species in several families. 'rhe habits,in regard to myiasis, of ~he species of any single family vary widely asmight be expected in groups which have become more or less specialized.For instance, the family Oestridae, which is the only family having all itsspecies concerned in myiasis, has members which infetlt the stomach, ot.herswhich develop in the nasal passages and still others which produce •cutancous myiasis. The family ~Iuscidae also exhibits very diverse habitsin this regard, some members being concerned in destructive myiasis,others in specialized dermal cases and still others arc blood suckers.Myiasis in animals is not generally considered in connection withhuman cases. There exists, however, a very intimate interrelationship;in fact, the prevention of myiasis in man is largely dependent upon thecontrol of the trouble in animals. Entomologists- engaged in sanitarywork must be prepared to handle insect attack on animals as well as onmM.iOwing to the need for careful determination of the exact species coneernedin cases of myiasis, both for the immediate needs of the cnse and forthe benefit of science, it is highly desirable that the larvre concerned bebred to adults whenever possible. Specific determination of the larvre,especially when small, is, to say the least, very difficult, but a few shouldbe preserved in alcohol for record and future identi6cation when larvalcharacters are better understood. Some suggestions as to breedingmethods arc apropos. There is no u!>c endeavoring to rear Oestrids afterextraction unless well matured. Most of the larvre from wounds willusually develop on beef. Care must be exercised in rearing the flies toavoid infestation of the material by other species, especially Sarcophagidswhich will drop larvre through screen wire onto meat or excrement. Adouble 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 shouldbe provided beneath the meat. The meat may be partially buried toretain moisture and reduce odor. It should be remembered, that the'larvre have It strong tendency to migrate when ready to pupate.TISSUE-DESTROYING FORMSIt should be said that most forms of larvre attacking man or animalsmay destroy body cells to some extent but not in the sense of the rapid. -.... ~ -_