GIPSY MOTH WORK IN NEW ENGLAND. 



17 



infested territory has been divided into five sections, and the towns 

 in which the points were located are indicated on the accompanying 

 map. 



Table III. — Gipsy moth egg clusters recorded in observation points, 1910-1914. 



Locations. 



Number 

 of points. 



Egg clusters. 



1910 



1911 



1912 



1913 



1914 



Eastern New Hampshire and Maine 



32 

 33 

 34 

 30 

 41 



2,074 

 14,885 

 29,399 

 10, 742 

 11, 486 



31, 751 



23, 032 

 47, 419 

 26, 409 

 39,319 



29,637 

 28, 618 

 30, 345 

 28, 301 

 42, 451 



26,147 

 9,603 



17, 603 

 9,763 

 8,222 



18.234 

 13,228 





31,316 





17, 159 





31,065 







Area, 30.18 acres 



170 



68, 586 



167,930 



159,352 



71,338 



111,002 







The count of the egg clusters recorded under 1910 was made in the 

 fall of 1911 and covered all clusters which were found to have hatched 

 and therefore belong to the 1910 brood of moths. This count was 

 more or less inaccurate, as many of the egg clusters were removed 

 from the trees after a year's exposure to the elements. The count 

 indicates, however, that there was a large increase in infestation 

 between 1910 and 1911, and that in 1912 the gross infestation was 

 slightly reduced. A heavy reduction occurred in 1913, while in 1914 

 a considerable increase was noted but not nearly as great as was the 

 case from 1910 to 1911. 



The conclusion which will inevitably be drawn from these figures 

 will not apply to other localities in the infested area. There are many 

 locations where a marked increase was noted in 1913 or where a 

 marked decrease was noted in 1914, but taking the territory as a 

 whole it gives a general idea of the trend of increase or decrease for 

 the period covered. 



Knowing the conditions, one can not fail to be impressed with the 

 results that have already become apparent from the introduction of 

 parasites and the work of the wilt disease. Although the season of 

 1914 was not as favorable to the natural enemies as was the case in 

 1910, the proportional increase in the number of egg clusters was 

 considerably smaller. Unfavored food plants have, of course, been 

 instrumental in holding down the increase in some of the points, but 

 the amount of infestation in points where unfavored food predom- 

 inates has remained rather constant, so that it has not been as great 

 a factor in the reduction noted as the other elements just mentioned. 



Much careful work has been required to secure this data. For 

 about six months in each year upward of 20 men have been engaged 

 in this work. During the summer a part of the men made observa- 

 tions on the feeding habits of the gipsy moth caterpillars on different 

 food plants in their sections. Observations on the presence of 



