8 REPORT ON THE DISEASES OP SILKWORMS IN INDIA 



an endeavour made to describe and define the diseases. In this, 

 as indeed in many of the much later works on sericulture, the 

 symptoms of several diseases were confounded together, and, as was 

 to be expected, only the more striking diseases and their most 

 characteristic appearances, such as the white efflorescence on the 

 mummified bodies of worms that had died of muscardine, were noted. 

 The significant point is, however, that at this early date in the 

 history olericulture in Europe disease was well established among 

 the worms and evidently not a thing of recent years. Subsequent 

 works on sericulture continued to pay attention to the question of 

 disease in European silkworms, and gradually many different forms 

 of sickness were recognized, some of them merely being names -for 

 what are now recognized as different symptoms of the same disease. v 

 ^It was not until the work of Pasteur in the years 1865-1870 that 

 order began to appear in the diagnosis and treatment of silkworm 

 diseases. Since his day much work has been done on this subject, 

 and a series of more or less well marked diseases are now recognized. 



The diseases of silkworms may be divided into two classes : those 

 caused by certain easily recognized animal and plant parasites, not 

 bacteria, and those of a more indefinite nature in which bacteria 

 may or may not play a part. For want of better names I shall 

 call the first group " parasitic diseases " and the second " rot 

 diseases/' Under parasitic diseases I include three diseases : — 

 (1) Pebrine. caused by Nosema bombycis, (2) Muscardine, caused 

 by Botrytis bassiana, and (3) the Fly pest, caused by Trigcolyga 

 bombycis. Under rot diseases I include all diseases of the flacherie 

 type and grasserie. The parasitic diseases are reasonably well 

 understood and their diagnosis and control are consequently 

 possible. The rot diseases, on the other hand, are somewhat 

 obscure in their origin and consequently imperfectly understood 

 and difficult to control. All these diseases are not equally 

 important in India. I propose to take them in turn devoting 

 space to them in proportion to their importance. When all the 

 diseases have been examined, we shall turn our attention to the 

 other silkworms found in India and rapidly run through the 

 diseases from which they suffer. 



1. KATA OR MATHA-KATA (PEBEINE). 



Definition and diagnosis. ^The name pebrine is in reality an 

 unfortunate one for this disease. Lit was given to it because of the 

 prevalence of black spots on the skin.) According to De Quatrefages, 

 who gave the name currency, pebrine in the language of the Midi 

 means '("pepper disease " — the black spots resembling pepper 



