HABITS OF J/6^S'C7iV,l STABULANS 209 



have been reared from the pupae of the cotton-wonn and the 

 Gipsy moth ; Riloy was of the opinion that in the first case rotten 

 pupae only were fed upon. In 1891 it was reared on the masses 

 of larvae and pupae of the Elm-leaf beetle. Other observers 

 record it as being reared from the pupae of such Hyuienoptera as 

 Lophyrns. 



The most complete account of M. stahulans is that given 

 by Portchinsky (1913). Reference has already been made to its 

 habit of destroying the larvae of M. domestica. This author states 

 that the larvae have been found not only in the excrement of man, 

 cattle and horses, but also in raw and cooked meat, on carcases of 

 different vertebrates such as mammals, birds and amphibians, on 

 invertebrates such as insects, their larvae and pupae, in rotten 

 bulbs and vegetables, in fungi and in old cheese, etc. Portchinsky 

 in his detailed account of the life-history and habits of M. stahulans 

 states that 160 eggs are deposited; they are spread singly or in 

 lines over the larval food. He confirms Bouche's statement that 

 the fly is able to pass through its developmental stages in about a 

 month, and thus several generations a year may be produced. 



The larva may reach a length of 11 mm. It is creamy white 

 in colour. There are two closely approximate mandibles. The 

 anterior spiracular processes are usually five-lobed (occasionally 

 six) and are somewhat like hands from which the fingers have 

 been amputated at the first joint. The posterior spiracles are 

 separated by a space less than the diameter of each ; they are 

 rounded, and each encloses three triangular-shaped areas con- 

 taining each a slit-like aperture. I have not been able as yet ta 

 study the complete life-history ; Taschenberg {t.c) states that it 

 occupies five or six weeks, but my observations would indicate 

 that this period can be shortened. 



The habits of this species which lead it to frequent excrement 

 and food render it a potential disease-carrier, as Portchinsky also 

 affirms. Banks (1912) records the passing by a child suffering 

 from diarrhoea of a considerable number of the larvae of this 

 species and refers to Laboulbene's record of the larvae of M. stahu- 

 lans being vomited by a person suffering from bronchitis. Carter 

 and Blacklock (1913) record the occurrence of the larvae in a case 

 of external myiasis in a monkey, together with the larvae of 



H. H.-F. 14 



