]50 Silkworms in India. [Vol. I. 



BOMBYX FORTUNATUS. > 



Desi or CJiota Polo. 



[ Plate VIII (C). ] 



This is a small multivoltine variety of the mulberry silkworm; it is 

 largely reai*ed in Bengal, where it yields the principal cold-weather crop 

 of cocoons. The cocoons are generally golden yellow in colour, and, 

 compared with the European annual variety, they are small and of loose 

 consistency. Cleghorn observed that the moths are dusky in colour, the 

 worm being fcluish-whitc without distinctive marking; while Hutton 

 noticed that the variety can be distinguished from all other varieties by 

 the fact that when near to maturity the caterpillar becomes of a dull 

 leaden blue colour. 



The following is an abstract of Mukharji's report upon the species: — 

 The rearers prefer a south aspect for the rearing house, but all rear- 

 ing houses do not face the south ; they are covered with specially thick 

 thatch, and generally have but one small window and a door. The window 

 is always kept shut at night, and during the cold season in the day time 

 also ; the door is always kept shut at night and in the cold weather all 

 chinks are carefully filled up, the fermenting refuse from the trays being 

 often piled up inside the rearing house to further raise the temperature. 8 

 In one rearing house in the cold weather Mukharji found as many as 

 thirty-two trays, each tray containing about 2,500 worms, besides a 

 man with his wife and children and a cow. He does not give the dimen- 

 sions of the house, but notices that this was rather an exceptional case, 

 the rearing house being generally set apart for the worms, though one 

 or two men usually sleep in it with the idea of protecting the worms 



tion by germs of disease from other establishments. In order to obtain the necessary leaf 

 for this early rearing, the mulberry is forced by manure to produce leaf earlier than it would 

 otherwise do ; but the supply is sometimes insufficient. Mukharji mentions other seed- 

 rearing establishments, where the percentage of disease is reduced by raising the insects in 

 isolated localities. 



1 Bombyx fortunalus, Hutton : Trans. |Ent. Soc, Lond. (3), ii, p. 312, pi. 19, fig. 3, 

 (1864-68).. 

 „ Hutton : Journ. Agri.-Hort. Soc, Tnd., iii, p. 125 (1871). 

 „ Moore: Proc. Zool. Soc, Lond., 1867, p. 683. 

 „ Wardle : Wild Silks of India, p. 3 (1881). 



Rondot: L' 'Art de la Suie, Vol. I, p. 312 (1885). 

 „ Mukharji : Report duted 6th January 1888. 

 „ Cleghorn : Letter dated i)th April 1888. 

 "The necessity of keeping up the temperature in the rearing houses, during the cold 

 weather, is shown by the failure of Mukharji's attempt to rear worms in some old bai racks 

 without following the usual method of keeping the place warm. 



