GIPSY MOTH WORK IN NEW ENGLAND. 3 



assistants and collectors were engaged to obtain parasitized material 

 which was forwarded to the Gipsy Moth Laboratory at Melrose 

 Highlands, Mass. After the completion of the foreign work in 1912, 

 it appeared that not only were the parasites, and a contagious dis- 

 ease known as the "wilt," prime factors in controlling the gipsy 

 moth in Europe, but in addition to these a pronounced obstacle to 

 the increase of the pest arose from the fact that forest conditions, 

 particularly in Germany, furnished in the main unfavorable food for 

 the caterpillars. The observations indicated that this factor, in 

 addition to the natural enemies already mentioned, was responsible 

 for rendering the gipsy moth of slight importance to forest growth 

 except at periodic intervals. 



In 1912 a number of areas were under observation by Mr. Worthley 

 in the forests of Germany, and at that time the infestation was severe. 

 Deciduous trees in these areas were defoliated and in some cases 

 many trees completely denuded of foliage. Similar studies were 

 made by Mr. Fiske in Italy, where a few infestations were found 

 which were more serious, if possible, than those observed in the Ger- 

 man forests. During the summer of 1913 no agent of the bureau 

 was engaged in making foreign observations on the gipsy moth. It 

 seemed best in the spring of 1914 to have the areas in Germany 

 revisited for the purpose of determining the result of the previous 

 infestations and to secure data on the increase or the decrease of the 

 species. Accordingly, early in the spring of that year, Dr. John N. 

 Summers, who for a number of years had been in general charge of 

 the parasite work at the Melrose Highlands Laboratory, was detailed 

 to visit the areas mentioned and to secure all the data possible on the 

 fluctuations of the gipsy moth, as well as to obtain parasitic material 

 for shipment to this country, in case it could be found in collectible 

 quantities. The result of this work has been reported by Dr. Sum- 

 mers, and it appears that in no place in Germany where the insect 

 was reported in 1912 was there a severe or even moderate infestation 

 in 1914. It was impossible, therefore, to obtain parasitized material, 

 and in most cases the insect was so rare that little data beyond the 

 mere fact that it still existed in the areas could be secured. 



About the middle of June a report was* received that a heavy infes- 

 tation of the gipsy moth occurred in the Province of Bereg, Hungary. 

 This information was received from Dr. Josef Jablonowski, and Dr. 

 Summers was instructed to take up his investigations in that region. 

 Unfortunately it was impossible for him to arrive in the infested 

 forest until after the feeding of the caterpillars was finished and most 

 of the eggs for the new brood of moths had been laid. Parasites were 

 not present to any marked extent at this time, which was not sur- 

 prising, owing to the fact that the observations were made too late 

 in the season. Some evidence was secured that the wilt disease was 

 present in the area, but a fairly good increase of the species was noted 

 except at points where the trees had been completely denuded and 

 where the caterpillars had died from starvation or had moved to 



