26 , IMPORTED PARASITES. 



The history of its introduction into America is most interest- 

 ing, and, except for the fact that it was so long delayed in ex- 

 ecution, forms one of the most satisfactory episodes in the entire 

 work of parasite introduction. 



As long ago as the spring of 1907 a few dead adults were se- 

 cured in an importation of gypsy egg masses received during the 

 winter from Japan, but none were living on receipt. During 

 the winter next following larger importations were made, and 

 many thousands of eggs, from which some parasite had issued, 

 were found, but not a single living specimen was obtained. It 

 was evident that it completed its transformations and issued in 

 the fall, and that, if it hibernated in the eggs, it was warmed to 

 activity while the packages were in transit to America, and the 

 adult parasites either died or escaped en route. 



In the fall, winter and spring of 1908-09 a large quantity of 

 eggs of the gypsy moth were received from Japan, the shipments 

 beginning early in the fall and continuing until nearly time for 

 the caterpillars to hatch in the spring. The first, received in 

 September, contained hundreds, possibly thousands, of the para- 

 sites, which had issued from the eggs en route, and all of which, 

 as usual, had died ; not a single living individual was received. 

 Specimens were referred to Dr. Howard, who found that they 

 represented an entirely new and hitherto undescribed species, 

 which he named after Professor Kuwana, who collected and sent 

 the eggs from which they had issued. A single pair of living 

 specimens rewarded the careful attention which was lavished 

 upon the importations received later in the fall and during the 

 winter, and it was not until April, 1909, that a mated pair could 

 be secured. During that month a total of 11 individuals issued 

 from cages containing Japanese eggs recently received. 



This small number served as the beginning of a series of ex- 

 periments in propagation, which succeeded so well that in Au- 

 gust several thousands were available for liberation in the field. 

 In September and again in October additional colonies were es- 

 tablished, and during the fall, some 50,000 in all were given 

 their freedom. 



After September the bulk of those reared were kept for exten- 

 sive propagation work in the laboratory, and at the present time 

 (February 1) a conservative estimate of the number in various 



