254 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



of towns adjoining the infested border and cleaning up the infested 

 areas in two or three tiers of towns inside the border has been con- 

 tinued. Special attention in these towns has been paid to discover- 

 ing and stamping out infestatLons on high elevations, as it is neces- 

 sary to keep such areas free from small caterpillars if serious wind 

 spread to new territory is to be prevented. 



'J'he new sprayers delivered this year are the most powerful that 

 have yet been employed. It has been possible to spray areas on 

 high elevations by locating the truck at the water supply and forcing 

 the spray material in some cases through a mile of li inch hose. 

 It has sometimes been necessary to maintain a pump pressure of 

 1,000 pounds in order to spray high elevations with such long leads 

 of hose, but this has been accomplished satisfactorily and economi- 

 cally, when the loss of time and delay that would be experienced in 

 hauling water such long distances is considered. Furthermore, in 

 many cases hose lines had to be laid through woodland and rough 

 areas where water for spraying could not be hauled. 



Spraying operations were conducted in 40 towns during the month 

 of June, as follows: New Hampshire, 22; Massachusetts, 10; Rhode 

 Island, 1 ; Connecticut, 7. 



Present condition of the area infested by the gipsy moth and 

 THE BROWN -TAIL MOTH. — It was apparent in the fall of 1917 that 

 serious defoliation by the gipsy moth would result in many parts 

 of the infested area. Conditions were particularly bad in the Cape 

 Cod region in Massachusetts, but severe defoliatix)n was looked for to 

 a less extent in limited areas in other parts of the territory. 



Climatic conditions during the winter were more severe than had 

 been experienced in New England for many years. Unusually low 

 temperatures were accompanied in many localities by abnormally 

 low humidity. In most sections a heavy snowfall occurred about the 

 1st of December and in a large part of the territory the ground was 

 covered with snow throughout the winter. This interfered seriously 

 with field work. 



The weather became very warm in May, which resulted in cater- 

 pillars hatching considerably earlier than during the two or three 

 previous years. Later it was noted that many egg clusters which 

 were fully exposed and which were not protected by snow or debris 

 on the ground failed to hatch. This condition was investigated, and, 

 while in certain sections it seems probable that egg parasites and 

 other factors had brought this result, it is undoubtedly true that the 

 abnormally severe weather during the winter caused a material re- 

 duction in the infestation in many localities. 



The hatching of egg clusters was more perfect in the Cape Cod 

 section in Massachusetts than in any other part of the territory, and 

 severe defoliation resulted there during the summer. In some parts 

 of the infested region where there was a minimum of snow protec- 

 tion combined with high altitudes the hatching was so deficient that 

 spraying was not attempted. This abnormal condition, while reduc- 

 ing the gipsy moth infestation in some sections, may have had a simi- 

 lar effect in reducing the increase of some of the introduced natural 

 enemies, particularly the egg parasites. Definite information on this 

 phase of the problem can not be secured until later in the season. 



