DEVELOPMENTS OF YEAR 1910. 311 



THE DEVELOPMENTS OF THE YEAR 1910. 



At the beginning of the year 1910 the statement was made that if 

 the parasites maintained the rate of progress which was then indi- 

 cated by the results of the recent field work, the year 1916 would see 

 the triumphant conclusion of the experiment and the automatic con- 

 trol of the gipsy moth through parasitism. This prophecy was also 

 dependent upon the measurable success of the importation work 

 which was' planned for 1910. 



The importations of 1910 were disappointing, and did not result in 

 the colonization of the few parasites which have not yet been liberated 

 in America under satisfactory conditions. Neither has the progress 

 of the parasites in the field been quite as satisfactory as was hoped 

 and expected. 



The failure of Schedius to demonstrate as clearly as might be 

 wished its ability to survive the winter was the first unfavorable 

 development in 1910. Recovery of Apanteles fulvipes, while not 

 expected, was hoped for, and although its nonrecovery can not be 

 considered as surely indicative of its inability to establish itself here 

 it is none the less disquieting. Discovery of the error in identity 

 which had resulted in misapprehensions concerning the status of 

 Tricholyga grandis was a serious blow to expectations concerning the 

 future of this species. Most serious of all was the nonrecovery of the 

 important brown-tail moth parasite, Parexorista chelonise, which was 

 considered to be thoroughly well established at the close of the sea- 

 son of 1909. Similarly, the failure of Monodotomerus to increase in 

 efficiency to the extent which was expected, was viewed with appre- 

 hension, as possibly indicative of what might result with others of 

 the imported species. 



To offset these several and various reverses was the unexpectedly 

 satisfactory increase in abundance and dispersion of Calosoma. 

 Anastatus did better than was expected in the matter of increase in 

 numbers and in effectiveness and slightly better in dispersion. Bleph- 

 aripa was recovered, when recovery was not expected so soon follow- 

 ing its liberation, and Compsilura was considerably more abundant, 

 and promised more efficient assistance than h?,d been hoped for. 

 Among the brown-tail moth parasites, Apanteles gave evidences 

 of a more rapid increase and wider dispersion than was expected, 

 and Meteorus was also unexpectedly abundant over a limited area, 

 and later showed evidence of rapid dispersion. The recovery of 

 Zygobothria nidicola, after its disappearance for two or three years, 

 was the most satisfactory and unexpected of the favorable results of 

 the season's field work until the recovery of Pteromalus in the fall 

 and during the winter. Although this latter is not an important 

 parasite, its nonestablishment was practically con-ceded, and the 



