140 



Accidental or Facultative Parasites 



102. Muscina stabulans (x4). After Graham 

 Smith. 



Muscina stabulans is re- 

 garded by Portschinsky 

 (19 13) as responsible for 

 many of the cases of intesti- 

 nal myasis attributed to other 

 species. He records the case 

 of a peasant who suffered from 

 pains in the lower part of the 

 breast and intestines, and 

 whose stools were mixed with 

 blood. From November until 

 March he had felt particu- 

 larly ill, being troubled with 

 nausea and vomiting in addi- 

 tion to the pain in his intestines. In March, his physician prescribed 

 injections of a concentrated solution of tannin, which resulted in the 

 expulsion of fifty living larvse of Muscina stabulans. Thereafter 

 the patient felt much better, although he suffered from intestinal 

 catarrh in a less severe form. 



Calliphorinse — Closely related to the Sarcophagidas are the 

 CalliphorincB . to which group belong many of the so-called "blue 

 bottle" flies. Their larvEe feed upon dead animals, and upon fresh 

 and cooked meat. Those of Pro- 

 tocalliphora, already mentioned, 

 are ectoparasitic on living nestling 

 birds. Larvae of Lucilia, we have 

 taken fromtimiors on living turtles. 

 To this sub-family belongs also 

 Aucheromyia luteola, the Congo 

 floor maggot. Some of these y 

 and at least the last mentioned, 

 are confirmed, rather than faculat- 

 tive parasites. Various species of 

 Calliphorinas are occassionally met 

 with as facultative parasites of 

 man. 



Chrysomyia macellaria, the screw worm fly (fig. 107), is the fly 

 which is responsible for the most serious cases of human myasis in 

 the United States. It is widely distributed in the United States 



103. Lucilia cassar. (x3). After Howard. 



