CLA SSIFICA TION OF DIP TERA . 3 1 



The characters of Musca are defined in the following manner : 



Cycloraphic caiypterate Brachycera, with a soft, fleshy proboscis without 

 lancets, developed from a larva with a single pair of anal feet, a rudimentary 

 head provided with two strong hooks, and with two pairs of spiracles, one pair 

 in front and the other near the posterior end of the body. The adult insect has 

 a long bristle on the third joint of the antenna fringed with short hairs on both 

 sides quite to its tip. The three subgenera, Lucilia, Calliphora, and Pollenia, 

 are distinguished from Musca, as defined above, by very trivial characters. 



The following description will serve to identify Calliphora erythrocephala: 



Calliphora erythrocephala is the commonest British species ; it measures 

 6 to 12 mm. (j to \ inch) in length, and 20 to 30 mm. from tip to tip of 

 the extended wings. Head, black, except the semicircular space between 

 the proboscis and the antennae, which is brown or black, and the genas, 

 which are fulvous or golden-yellow ; beard, black. The back of the head 

 and sides of the forehead often have a silvery pubescence. 



Thorax, blue-black, with white pubescence above on each side. Wings, 

 diaphanous and smoky, with black nervures ; nervures near the thorax, tes- 

 taceous ; legs black. 



The wings and the tarsi in some lights always have a rufescent pubes- 

 cence, which in specimens from Eastern Europe is very well marked, and 

 extends over the back of the thorax. The abdomen is of a deep metallic- 

 blue, the anterior three-fourths of each segment being covered with white 

 pubescence. 



Sometimes both thorax and abdomen are violet with a greenish sheen ; 

 possibly such insects are hybrids between C. erythrocephala and the allied 

 C. cognata. 



C. erythrocephala is sufficiently distinguished from all other Calliphoras 

 and Lucilias by its fulvous genae, black beard and blue-black abdomen. Some 

 of the numerous allied genera might be mistaken for Calliphora, but differ 

 in the nervures of the wing. 



Calliphora vomitoria is rare in England, and has a red beard and black 

 cheeks ; in most anatomical works it is confounded with C. erythrocephala. 

 The genus Lucilia is distinguished by the blue-green metallic lustre of the 

 abdomen in these insects. 



According to Portchinski [15], who investigated the larva; of many species 

 of Muscidae in both North and South Russia, the larvae of Lucilia ccesar and 

 Cynomyia mortiiorum are all exclusively carrion feeders and live entirely 

 upon flesh, whilst those of Musca domestica and Musca coruina are copro- 

 phagous. The above-mentioned carnivorous larvae are all so much alike 

 that Portchinski was unable to find any difference in them. 



Musca corvina differs from all the rest in the large size of its eggs. This 

 insect lays only twenty-four eggs, and the larva only exhibits two instead of 

 three stages in the development of the spiracles. 



Musca corvina is exceedingly abundant in the Crimea and the Caucasus. 

 Early in spring these flies are oviparous, but in the late spring and summer 

 they are viviparous, and deposit larvae in the third stage of development. 



Portchinski ventures on the hypothesis that the Pupiparas were originally 

 coprophagus insects in the larva state, and laid an almost full-grown larva, 

 like Musca corvina. 



