38 , C. SASAKI. 



possible, such trees should be removed and new and vigorous trees 

 planted in their place. In any case, the leaves of such old and ex- 

 hausted trees should be given to the silkworm before its third moult, 

 as the fly does not deposit its eggs till after that time. 



6th. To avoid the visit of the fly, it seems better to plant mul- 

 berry trees in separate rows • parallel to the direction of the prevalent 

 ■wind in May. 



7th. The raising of the summer and autumnal breeds of silk- 

 worms with the leaves which have sprung out later than the month of 

 June would answer best the purpose of escaping the damages of the 

 parasite. But stripping ofl:' the leaves at this season is very injuri- 

 ous to the growth of mulberry trees, and also the later breeds are much 

 inferior in their growth to the spring breed, so that it is still most 

 advantageous to raise the spring breed alone with great care and giv- 

 ing the leaves of the best sort. 



8th. The silkworms afilicted by the diseases of Umiko, Tareko, 

 Fushidaka &c. and which are not likely to spin the cocoon should be 

 killed by putting them into salt or lime water, for most of them contain 

 the Uji. 



9th. In the month of May and June the flies wander in the 

 bushes of mulberry trees for the deposition of their eggs. No pains 

 should be spared in catching and killing them, for a single female may 

 be able to deposit about six thousand eggs. 



10th. Besides the silkworm, there are larv£e of other moths which 

 are infested by the maggot of the same fly: — one is Ivuwako (larva of 

 a wild silkworm ) which feed on mulberry trees, and another is the 

 larva of Laurion atratus, Butler, which feeds on Simplocus cratezoides, 

 Don. The specimen of the latter I have received from my friend Mr. 

 C. IshikawQ. The larvfc of both should be caught and killed. 



11th. The pupa of the silkworm and the maggot imprisoned in 



