THE CANADIAN ENTOMOLOGIST. 413 



A CASE OF PSEUDOPARASiriSM BY DIPTEROUS LARV.^. 



BY WILLIAM A. RILEY, CORNELL UNIVERSITY. 



Recently a medical friend, Dr. A. K. Ayler, called my attention to 

 some "worms" which he had found under peculiar conditions. 



A patient, an elderly lady of one of the best fariiilies, was suffering 

 from a malignant tumor — a melanotic sarcoma — located in the small of 

 the back. The tumor was about the size of a large walnut. On exam- 

 ination the doctor was surprised to tind, close to the stalk and between 

 the tumor and the body, some ten or twelve "worms," which were feeding 

 upon the diseased tissues. Although they had irritated and caused a 

 slight hemorrhage, neither the patient or others of the family knew of their 

 presence. Any discomfort which they had caused had been attributed to 

 the sarcomatous growth. 



Four of the specimens, which proved to be dipterous larvae, had been 

 preserved alive. Although they were for three days without food, they 

 pupated, and, about a week later, there emerged two adults of the genus 

 Sarcophaga. F'rom my knowledge of analagous cases I assumed that the 

 species was the common European S. carnaria, but on looking the matter 

 up more fully I find that this species does not occur in the United States, 

 and that the references to it "undoubtedly lefer to other species, probably 

 several" (Aldrich, Cat. N. Am. Diptera, p. 511). Dr. O. A. Johannsen 

 has kindly examined the flies for me. Unfortunately, the specimens were 

 females, but he states that they probably belong to an undescribed 

 species. 



The infestation occurred during the latter part of August. It is 

 probable that the adult was attracted by the odour of the discharges, and 

 deposited the eggs or living maggots upon the diseased tissues. This 

 might readily be accomplished so quickly as to completely escape notice. 



A number of analagous cases of larv?e of Musca erytJirocephala, and 

 of Sai-copJuiga carjiaria infesting the nasal passages, the auditory meatus, 

 or open wounds, are to be found in medical literature. Kuchenmeister 

 (Manual of Parasites, Eng. trans., 1857, Vol. 2, p. 98) states that in 

 malignant inflammation of the eyes the larvje of these two species even 

 nestle under the eyelids, and, in F'gypt, for example, produce a very 

 serious addition to the effects of smallpox upon the cornea. 



December, 1906 



