78 SCIENTIFIC REPORTS OF THE AGRICULTURAL RESEARCH 



1919, however, they may cause damage unless they can be 

 forestalled by a change in the planting time and also 

 changes in the methods of cultivation so as to avoid the ill 

 effects of drought on the setts lying in the ground. In this 

 connection it may be observed that the whole of the loss 

 sustained at Kamrup in 1919 was not attributable to these 

 beetles; a very careful examination of all the plots, made 

 at the time, showed that the beetles were not responsible 

 for a loss of more than about 20 per cent, of the crop. The 

 failure of setts to sprout owing to unfavourable climatic 

 conditions could not be ascribed to the beetles. Further 

 details of life-histories of these beetles, and especially the 

 question of their normal control by natural enemies, can 

 only be settled by further investigations on the spot. 



In March 1920 a few specimens of Autoserica sp. were 

 observed gnawing sugarcane shoots at Pusa in the same 

 manner as the Dynastine beetles at Kamrup. It appears 

 that this form of damage is possible by many Scarab?eid 

 beetles. 



In September 1919 the Entomological Assistant, Assam, 

 collected some grubs of Anomala dussumieri (Plate' VII, 

 fig. 1) amongst sugarcane roots at Kamrup and sent them 

 to Pusa. The grubs were reared up and were found to 

 hibernate as larvse, and pupated "and emerged as adult 

 beetles in April. Apparently therefore this beetle has 

 only one generation in the year. 



Tanymecus kispidus (Curculionidse) was sent in from 

 Kamrup as attacking young sugarcane shoots in April. 



Argyria tumidicostalis , Hmpsn., the borer referred to 

 in the Report for 1917-18 as C. S. 1610, which is one of the 

 most injurious of all the borers in sugarcane, was found in 

 May 1920 in cane at Sadiya, in Upper Assam, all of a 

 number of cane-borers collected there proving to belong to 

 this species, which is now known to occur at Pabna, Jorhat, 

 Dacca and Sadiya. It is to be hoped that it will not be 

 introduced into other parts of India and too great precau- 

 tions cannot be taken to prevent its transport in canes 

 exported from Assam and Eastern Bengal into other parts 

 of India. » 



