ENTOMOLOGY

MYIASIS-TYPES OF INJURY, LIFE HISTORY, HABITS 193The Anthomyid flies of the genus Fannia have been recorded as causingserious gastric disorders. Among the symptoms are abdominal pains,nausea, and 'V'tlmiting, and sometimes vertigo, headache, and bloody diarrhea.Fannia canicularis (plate VII, fig. 3; text figs. 14-16), commonlycalled the lesser house fly, and Fanmia scalaris (text figs. 17-19) arewidely distributed and breed in various types of decaying vegetable matterand excrement. We find that the larvre will feed upon and penetratemeat, and they may attack the living tissues to some extent.In the urogenital infesting group the above-mentioned species ofFannia, which are also known as the latrine flies, figure most prominently.These species are rather strongly attracted to human excrement, especiallyurine. This habit is undoubtedly responsible for the infestationof the genitalia. Such infestations must ~ertainly be attrib~ted to theexposure of the genitals in sleep by drunken or careless persons, or occasiOl('Jlyinfants. Robineau-Desvoidy has re.ported a case in which anOestrid larva was passed ftom the bladder by a woman. Kollar has reportedthe occurrence of a large number of larvre of the common housefly in the vagina of a diseased woman. Chevral has brought togethera number of records of" cases of myiasis of the genitalia.EURoPE.-Nearly all the above-mentioned forms are to be encounteredin r_~ts of Europe. In the ¥editerranean countries one wouldexpect to ]Yhd a greater number of forms leading to tllese types ofmyiasis.AFRIcA.-Several of the previously mentioned forms occur in Africa.The Oestrid larva, Pharllngobolus africanus Brauer, commonly attachesto the walls of the esophagus of the African elephant, and an Oestrid00 the genus Cobboldia (C. loxodontis Brauer and C. chrllsidiformisRodhain and Bequaert) are found in the stomach of the African elephant,and C. elephant is (Steel) Cobbold, attacks the Indian elephant ina similar way. Species -of Girostigma in the same family infest thestomach of the Rhinoceros. Anthomyia disgordiensis is said to be notinfrequently passed from the intestines of man in Angola.FORMS PRODUCING MYIASIS IN HEAD PASSAGESAll of the species included in this group are normally parasitic onanimals, and infestation of man, although not uncommon, must be consideredaccidental. In the lower animals the attack of these larvre isoften quite injurious though not usually fatal in itself. In man theprincipal injury sustained is in the effects on the eye when it happens tobe attacked.AMERICA.-In the United States as well as in all parts of the world,the sheep head maggot, Oestrus ovis Linnaeus, is the most important