22 IMPORTED PARASITES. 



It is not by any means assured that all of these parasites are 

 established here, but it is possible that they are, or that they 

 will be before another season passes. Some that are known to 

 be living in the field, and which are apparently in a very good 

 way toward becoming permanent fixtures in the American fauna, 

 have had their freedom for less than one year ; and there is no 

 assurance that a species is established until it has completed 

 at least one cycle of the seasons unprotected in the open. A 

 few of them, as will be shown later, will be the better for 

 artificial assistance in dispersion, etc. One, Chalcis, ought to 

 be imported in larger numbers, but with this one possible ex- 

 ception, each that is listed has been liberated under the most 

 favorable circumstances which it is possible to provide. 



Especial attention is called to the fact that the sequence is 

 comiplete as it stands. Every stage of the moth is provided with 

 a parasite which will attack it, if given the opportunity, and in 

 every respect the table compares favorably with that illustrative 

 of the Japanese parasites or of the European. It represents, 

 in this most important respect, the climax of the endeavors of 

 the past five years, and it has been accomplished only during the 

 past five months. If the writer were assured of the firm estab- 

 lishment of each of the species listed, and that each would be- 

 come as efficient in Massachusetts as it is in the countries from 

 which it came, he would state without reservation that the work 

 of parasite introduction was successfully accomplished. 



The reader must not confuse the accomplishment of parasite 

 introduction with the accomplishment of the end which it is 

 desired to achieve. It goes without saying, when the habits of 

 the parasites are taken into consideration, that the few paltry 

 thousands, which it has been possible to secure through methods 

 of importation which were the best which experience could 

 devise, must be allowed sufficient time to increase to the millions 

 and billions necessary to cope with the tremendous quantities 

 of gypsy moths which are everywhere in evidence throughout 

 the infested district, wherever the expensive methods of hand 

 suppression have not been employed. 



Eortunately, this increase, if it follows colonization, will be 

 by geometrical progression, exactly as has been the case with the 

 gypsy moth ; and it will, most fortunately, be much more rapid 



