GYPSY AND BROWN-TAIL MOTHS. 35 



the parasites were received at the laboratory, and it was possible 

 to allow the formation of the puparia under natural conditions 

 m the earth. Each preceding year the maggots had reached 

 their maturity, and formed, or attempted to form, puparia in 

 the boxes in transit. They were often injured, and the puparia 

 were always thoroughly dried when received. 



A Tery large number of the parasites were secured in this 

 manner (25,000, as a conservative estimate), and several thou- 

 sands of the maggots were allowed to enter the earth in the open 

 in forests infested by the gypsy moth. Examination has demon- 

 strated the fact that these maggots pupated in a perfectly natural 

 manner, and the condition of the pups at the present time is 

 far and away more satisfactory than it has ever been before at 

 this season of the year. It is almost impossible to conceive of 

 conditions which will prevent the emergence of these flies in 

 large numbers in the open the coming spring. 



The remainder of the maggots were allowed to go into the 

 earth in a variety of containers, principally sunken wire screen 

 cages in the laboratory grounds. They, as well as those in the 

 open, are in the best of condition, and it will be a severe dis- 

 appointment if a large number of the flies are not reared and 

 colonized, as a result. 



The parasite was colonized as adults in small numbers and 

 under satisfactory conditions in the spring of 1907, and in 

 somewhat larger numbers in 1908. No results have been secured 

 to date, nor are immediate results expected from these early 

 colonies. The fly is very strong, and it is to be expected that 

 it will fly for long distances during the considerable period of 

 its activity in the spring. Unlike Glyptapanteles, Schedius, 

 etc., it is not ready to deposit its eggs for something like three 

 weeks after it issues in the spring, and during this time it is 

 likely to traverse considerable distances. It is a source of great 

 regret that it has not been liberated in large numbers much 

 earlier in the course of the work; but it was not until after 

 numerous experiments had been made, through which it was 

 hoped to remedy the obvious defects in methods of importation 

 and handling, and all modifications proven to be useless, that 

 the extraordinary methods of last season were adopted. There 

 is not a single other one amongst the numerous species of 



