No. 4.] RKPORT OF STATE FORESTER. 331 



continuing such experiments till the precise methods of infection and of 

 its specific organism have been determined by carefully controlled labora- 

 tory experiment and protistological investigation. Such investigations 

 are being pursued, with improved facilities, by the federal Entomological 

 Bureau in co-operation with the Bussey Institution of Harvard University, 

 and may be expected to yield, in the not too distant future, some adequate 

 theoretical basis for a sound practical utilization of the disease in the field. 

 Very sincerely yours, 



W. M. Wheeler, 

 Professor of Economic Entomology. 



The Fungous Disease of the Brown-tail and Gypsy Moths. 

 The same co-operative arrangements, as heretofore, were made 

 with Harvard University, through Dean W. C. Sabine and Dr. 

 Roland Thaxter, for carrying on this work. Mr. R. H. Colley 

 was in charge assisted by some of our regular employees when 

 occasion demanded it. The work was carried on at the Harvard 

 Botanic Gardens, and we are greatly indebted to Harvard Uni- 

 versity for the use of their greenhouse and cold frames as well. 

 The following report by Mr. Colley explains itself: — 



Planting was commenced on the 6th of May, a week later than in previ- 

 ous seasons, on account of the late start of the larvae in the field and general 

 cold weather conditions, and continued until the 6th of June. Mailing 

 cases again were used for the distribution of the diseased caterpillars. 

 In sending out the material it was planned to supply the different districts 

 with infected larvae on definite dates, to ensure, as far as possible, that the 

 planting would be done immediately on receipt of the material. This 

 scheme was adhered to, with few exceptions. Approximately 200 cases 

 were shipped to State and town superintendents all over eastern Massa- 

 chusetts. The division superintendents supervised the work in order to 

 acquaint the town men with the proper methods of handling and planting 

 the material. Besides this distribution about 100 cases were shipped to 

 private individuals during the first week in June. 



The results of nearly all of the plantings were very satisfactory. In- 

 spection of the planted areas by local and division superintendents showed 

 that the disease had materially decreased the number of larvae, and in 

 some cases had killed practically all of them. Some failures were re- 

 ported, which were undoubtedly due to delay in transit or material sent 

 out when the infection in the disease boxes was low. Viewing the work 

 as a whole, the season may be said to ha-ve been very successful. The 

 results certainly seemed to indicate that a more extensive planting of the 

 fungus would be even more effective in reducing the numbers of the 

 caterpillars. 



