83 



not answer the question which is of most importance to the practical 

 agriculturist, namely: Can this disease be used as a practical means of con- 

 trol? That is, If the germs are sprayed on the food plants of the insect 

 will the disease be spread? Experiments were tried to determine this, 

 but they were not quite conclusive as will be seen from the following: — 



Cage F. 



June loth. — 12 tent caterpillars were put in a cage with abundance 

 of food. The food was sprayed with a suspension of the organism in 

 sterilised water. 



Jwie nth. — 1 dead. 

 June 1 2th. — 1 dead. 

 June 14th. — 1 dead. 

 June i/th. — 2 dead. 

 June i8th. — 1 dead. 

 June 20th. — 1 dead. 

 June 24th. — 1 dead. 

 June 25th. — 2 dead. 

 June 2/th. — 2 dead. 



It will thus be seen that all the caterpillars died within 17 days. 

 Unfortunately, however, a few of those in the check cage died also, so that 

 this cannot be regarded as final proof. It should be observed, however, that 

 the majority of the checks were alive after the death of the others. 



Several nests were sprayed in the field both with a pure culture and 

 with the crushed bodies of diseased caterpillars. Though many cater- 

 pillars died in these nests, little value can be attached to these results 

 as the wide occurrence of the disease at the time rendered doubtful any 

 positive results obtained in the field. 



It is hoped that this problem will be solved during the coming summer 

 and also the question as to how long an artificial culture of the organism 

 will retain its pathogenicity. 



2. A Disease of the White Grub. 



Professor Zae Xorthrup, of Michigan Agricultural College, published 

 a bulletin last fall entitled "A Bacterial Disease of June Beetle Larvae, 

 Lachnosterna spp." In it she describes for the first time a disease caused 

 by Micrococcus nigrofaciens Xorthrup. The knowledge of the occurrence 



