48 REPORT ON THE DISEASES OF SILKWORMS IN INDIA 



extraordinary difference in caterpillar mortality given in Experi- 

 ment 19, lots la-lc, are conclusive proofs of the value of the 

 right food and enough of it. The second lots in Experiment 19 

 show the same results for rather different materials — here again 

 generous feeding showing great improvement in the worms and the 

 cocoons. The last experiment of the series was done on healthy 

 caterpillars, and here the effect of underfeeding is seen in the slower 

 and somewhat irregular growth and the poor cocoons produced. 

 The effect of dirty leaf is shown in the same way but especially in 

 the poor quality of the cocoon. The interesting point in this ex- 

 periment being that the improperly fed ones gave quite the appear- 

 ance of slightly pebrinised worms — slower, rather irregular and poor 

 cocoons — if to this had been added overcrowding, the result would 

 have been a product similar to what the average rearer gets and 

 which is frequently put down to the fault of disease. 



Thus it will be seen that sufficient food especially of a certain 

 quality is of immense benefit to the silkworm. If the ryots 

 would only feed their worms more liberally they would get better 

 cocoons and, if there was no disease among them, a better yield of 

 cocoons. If they could only be induced to use a little tree mulberry 

 the results would be still more satisfactory. In this connection it 

 is important to note that the good effect of the tree mulberry was not 

 very noticeable until after the 4th moult, so that if caterpillars could 

 be " finished' off " on the leaf of tree mulberry the benefit would be 

 great. It is further to be noted that the so called " trees " used in 

 my experiments were only a stem of a bush plant which was allowed 

 to grow up for about a year, while the other stems were kept cut, so 

 that there is no real difficulty in getting tree leaf. With regard to 

 more frequent feeding it may be mentioned that in Madagascar the 

 young caterpillars are fed 8-10 times a day, older caterpillars 6 times 

 a day and in the last stage they are never left without leaf. In 

 Bengal about 4 or 5 times a day is the most they are ever fed and they 

 are frequently seen with nothing but withered leaf or bare twigs 

 on the trays. In Mysore the worms are fed at least 7 times in the 

 24 hours, including 3 feeds at nights, and they certainly show the 

 benefit of the extra care. 



Hill amelioration. In most sericultural countries, especially 

 where univoltine worms are reared, it is considered beneficial to use 

 seed which has been bred in the more elevated parts of the country. 

 It has been suggested, therefore, that in order to supply the plains 

 of India with seed, stations should be established in the hills where 

 this " hill ameliorated " seed would be produced. The question is 

 a very difficult one, and one which cannot, I think, be determined 

 off-hand. It is certain that the hot and moist valleys of the Ganges 



