211 



Sweet potatoes reared from cuttings obtained from an area free 

 from the beetle, Euscepes {Cryptorrhynchus) hatatae, showed only slight 

 infestation, which was not the case with those on small holdings 

 where these precautions had not been taken. Efforts are being made 

 by the Agricultural Department to provide non-infested cuttings in 

 the hope of eradicating the pest in the course of a few years. Several 

 minor outbreaks of the caterpillar, Protoparce cingidata, were 

 experienced. 



Grubs of Lachnosierna sp. attacked the onion and maize crops, 

 the corn ear worm {Heliothis ohsoleta) being also invariably present 

 on the latter. 



De (M. N.). Second Report on the Experiments carried out at Pusa to 

 improve the Mulberry Silk Industry, compiled under the Direction 

 of the Imperial Entomologist. — Agric. Research Institute, Pusa ; 

 Calcutta, Bull. no. 74, 1917, 27 pp.. 12 tables. [Received 20th 

 March 1918.] 



Multivoltine hybrid races of silk-worms have been successfully 

 established. The yield of silk from these is better than that of the 

 pure multivoltine races generally reared in Bengal, Assam and Mysore. 

 It has been found that all races yield more silk if fed wath suitable 

 tree mulberry leaves than when fed with bush leaves, hence tree 

 mulberries should be introduced into all localities in addition to bush 

 plants. 



Of all the indigenous races, the Mysore race is the best as regards 

 the yield of silk. The Nistari race should be reared in April or May, 

 the Mysore and hybrid races from July to October, and imivoltine 

 races from October to March. 



Of all the univoltine races, the Chinese and Japanese ones thrive 

 best in a climate like that of Pusa, but their yield of silk is inferior to 

 those of France and Italy. 



Univoltine eggs should be hibernated for about 4 or 5 months at 

 about 35° to 45° F. Though the duration of cold storage can be 

 shortened by the action of intense cold, this and a fluctuation of 

 temperature in the hibernating chamber render the hatching of the 

 eggs unsatisfactory. 



As regards the silk-worm diseases flacherie and pebrine, experiments 

 have proved that eggs laid by moths attacked by flacherie can be 

 used for industrial purposes, but that a pebrinised laying will yield 

 good crops and healthy layings only if the worms are carefully attended 

 to, and if the temperature and moisture- content in the air are suitable 

 for the healthy growth of the worms. On the other hand, bad crops 

 and pebrinised layings result from a healthy laying if the temperature 

 and moisture-content are high, and if the worms are not properly 

 looked after. Pebrine is more prevalent in May to October than 

 from September to April, univoltine races being more susceptible 

 to it than multivoltine ones in a climate like that of Pusa. 



An improvement in the cocoons of univoltine races by immersing 

 the eggs in dilute hydrochloric acid having been reported from Japan, 

 the eggs of a multivoltine race were experimentally treated on these 

 lines, but with negative results. 



(C463) o2 



