ON THE PARASITIC FLY ON THE SILKWORMS IN CHINA. 



27 



maggot. 



houses of silkworms, deposits its eggs directly on the body of the host and 



further Mr. N. Todoroki, who has attended to silkworm culture during several years 



at Köshin in China, informs me of the same fact and that he has obsorved actually 



the deposition of eggs by the fly on the body of silkworms in a breeding house. 



On examining the silkworms infested by the maggot, we can observe a number of 



brownish black patches of variable sizes, everywhere on the dorsal as well as the ventral 

 Fig. 3. 



portion of the body (fig. 3, a, b,c). 

 Tightly attached to the surface of 

 each of these patches, may be found 

 a single egg of the fly (fig. 4) 

 The eggs are elongated oval and 

 less than a millimeter in length. 

 All of the eggs look almost trans, 

 parent, owing to their being empty, 

 the maggot having already hatched 

 out. The egg shell is marked 



allover with characteristic hexagonal areas. On a portion of the patch, where the 

 Fig 4. 



egg is attached, remains always a minute perforation, which is 



unquestionably the passage of the maggot into the body of the 



silkworm. The maggot is usually found directly beneath the 



patch above mentioned. It is usual that more than a single 

 egg. 



maggot live parasitic in a silkworm, since there may be several brownish black 

 patches on the body of the latter, while in the case of the fly in our Japanese silk- 

 worms there is only a single maggot in one host. 



It is said that the parasitic flies in China destroy largely the silkworms at the 

 5th stage of their development, or after the spinning of cocoon. In the latter case, 

 the maggot gets out of the cocoon by making perforations in it, which make the 

 cocoon entirely useless for reeling. 



Upon our wild silkworm (Theophila mandarina Moore) there maybe found a 

 parasitic fly which appears to be the same species as 7 ach ina rmiica of China ; but 

 it never enters our breeding house and becomes parasitic upon our domestic silkworms. 



