PRESENT STATUS OF INTRODUCED PARASITES. 307 



with the utmost assurance that if a sufficient number and variety of 

 parasites and other natural enemies of the gipsy moth which act in a 

 manner comparable to the true facultative parasites, as above de- 

 scribed, can be introduced into America, the automatic control of 

 the gipsy moth will be permanently effected. 



During the past four years the "wilt" disease has been increasing 

 somewhat in efficiency, but notwithstanding that it is and has been 

 prevalent in every locality in which the gipsy moth has been allowed 

 to increase unchecked, the gipsy moth still continues to be a menace 

 to the life and health of valuable trees which have been protected 

 during this time at a considerable cost. In parts of Russia, where 

 parasitic control is obviously inefficient, control through disease is 

 not sufficient to keep the gipsy moth from increasing until defoliation 

 of large areas results. Similarly, in America, the destruction of very 

 large numbers of caterpillars of several sorts of the larger Lepidoptera 

 has been observed, but in no instance until after the caterpillars 

 involved had increased to such numbers as to become a pest. 



It may be that the parasites already introduced and established, 

 or likely to become established, will prove to be sufficient for the 

 purposes intended. Only events themselves can be depended upon 

 to answer this question, and from five to six years must pass before 

 the answer is known. During this period the gipsy moth will con- 

 tinue to disperse and multiply, and large expenditures will be neces- 

 sary to prevent much more rapid dispersion and multiplication than 

 has prevailed in the past. 



Expenditures amounting to a very small percentage of the total 

 will suffice to carry on the parasite work. If the parasites already 

 introduced are sufficient to meet the needs of the situation, the 

 expenditure projected will have been needless and unnecessary. If 

 the parasites already introduced are not sufficient, it may be that 

 this deficiency can be made up in time to avoid much if any delay 

 in the day of final triumph. 



THE PRESENT STATUS OF THE INTRODUCED PARASITES. 



PARASITES OF THE GIPSY MOTH. 



EGG PARASITES. 



Anastatus bifasciatus Fonsc. 



Received first in 1908. Colonized unsuccessfully in 1908 and successfully in 1909. 

 First recovered in immediate vicinity of colony in 1909. Increased notably in 1910, 

 but indicated dispersion is only about 250 feet per year. Artificial dispersion neces- 

 sary. Apparently well established. 



SCHED1US KUVAN.E HOW. 



Received first in 1907, dead, and in 1909, living. Successfully colonized in 1909. 

 Recovered in immediate vicinity of colony site in 1909. Doubtfully recovered in 

 1910. Establishment very doubtful on account of climatic conditions. 



