PROCEEDINGS OF THE THIRD ENTOMOLOGICAL MEETING 829 



presses the opinion that a moth examined on the day after oviposition will 

 he sufficiently infected to enable one to detect the pebrine corpuscles. 

 I cannot possibly think this to tally with our results. Mr. N. G. Mukerj ee 

 in his Handbook of Sericulture clearly stated that no examination, except- 

 ing that in the winter season, can be said to be perfect, for in other 

 seasons the number of days at our disposal for the examination is too 

 short to enable the development to be sufficiently advanced so as to be 

 detected in the earlier stages of the moths. This is quite true, as we 

 iave ourselves noticed that the percentage of pebrine increases — or 

 rather, the detection becomes more efficient — the longer we wait (as 

 long as possible) and have our examinations on the day previous to 

 hatching, or, if we have too many moths to examine, this is done a day 

 or two earlier but seldom before the sixth day. Even with such strict 

 measures we are helpless in combatting this disease to a large extent. 

 Had it not been for the elucidation of this problem ' by the work of 

 Mr. C. M. Hutchinson we would have been at a loss to account for the 

 reasons. Mr. Hutchinson's experiments have enabled us to ascertain the 

 causes and at the same time have offered an easy solution to this difficult 

 problem. 



In our examinations of the pupae we have not been able to estimate 

 properly the exact nature of the proportion of the disease. For selecting 

 a lot for seed-purposes we generally try a number of pupae and if the 

 percentage be above two to three per cent, in the pupae the lot is re- 

 jected altogether for seed-purposes and subsequent examination in the 

 moth stage. A fresh lot is selected. In many cases even when the 

 pupae showed no pebrine, it afterwards turned out that the moths 

 had shown about 10 per cent, disease. There can be no question of the 

 drawbacks for using paper in the case of pupae. The examination of 

 the guts, however, revealed the existence of pebrine. 



In Europe, where univoltine races are reared, there \i a lesser accu- 

 mulation of pebrine germs for infection before the next rearing is com- 

 menced. So that the chances of outward infection are very little, whilst 

 in Bengal, where multivoltine races are reared, the germs are constantly 

 being accumulated, as one crop follows another in quick succession. 

 In our May to August crops the larval period is finished in twenty days 

 and the moth emerges out of the cocoon within seven to eight days. 

 There is nothing analogous to Such rearings in Europe. Apart from 

 these facts, the conditions in India are not similar to European condi- 

 tions. I would like also to point out that even in Europe with all such 

 advantages pebrine has not been totally eUminated from scientific 

 grainages. This may not necessitate such strict measures in Europe ag 

 they are more favourably circumstanced than what we may expect to 



