256 ANNUAL REPORTS OP DEPARTMENT OF AGRICULTURE. 



has progressed so far that attempts have been made to colonize it in 

 the field, but the results of these colonizations will not be apparent 

 for another season. Data are being secured on the prevalence of the 

 wilt disease of the gipsy moth, but it has not been as abundant or 

 destructive to the caterpillars this year as heretofore. 



Silvicultural investigations on the sample plots are being continued. 



Quarantine work. — The inspection of forest and quarry products 

 and nursery stock has been continued during the past year, although 

 the volume of this material is not as large as that inspected hereto- 

 fore. This is particularly true in connection with the shipments of 

 nursery stock. From the number of gipsy-moth egg-clusters inter- 

 cepted on material that was offered for shipment, it is evident that 

 this work must be effectively and thoroughly performed if the insect 

 is to be prevented from spreading to points outside the infested area. 



Summary. — The most severe infestation of the gipsy moth is at 

 present in the Cape Cod district in Massachusetts. While the area 

 infested by this insect has increased during the past year, the severity 

 of infestation along and adjacent to the border is less severe than 

 heretofore. The effectiveness of the imported parasites and natural 

 enemies of both the gipsy moth and the brown-tail moth is increasing, 

 although the severe winter conditions during the past year have been 

 unfavorable to some of the species concerned. The area infested by 

 the brown-tail moth has decreased materially, and the insect is not 

 now seriously destructive except in limited localities. 



Considering the area as a whole, conditions are favorable at the 

 present time to bring about a marked decrease in the abundance and 

 destructiveness of the gipsy moth. 



