OF WASHINGTON. 61 



a successful hibernation in numbers of the parasites. As a mat 

 ter of fact, however, this was what occurred. The eggs of the 

 Orgyia hatched in considerable number in the spring of 1896 and 

 on account of an extremely successful hibernation of parasites the 

 first brood was practically annihilated. The percentage of para 

 sitism must have reached 98 or 99 per cent. In August it was diffi 

 cult to find a single larva of the Orgyia. He exhibited a named 

 series of the parasites reared, filling three Schmidt insect-boxes. 

 He discussed at some length the interrelations of these parasites, 

 showing the important point that while in the fall of 1895 primary 

 parasites were by far the most abundant, during the summer of 

 1896 secondary or hyperparasites practically destroyed the primary 

 parasites after their important work of exterminating the Orgyia 

 had been accomplished. He also called attention to one or two 

 cases of tertiary parasitism. 



In discussion, Mr. Schwarz asked whether the primary para 

 sites noticed were any of them restricted to this species or were 

 forms which parasitized other Bombycid larvae, and upon the 

 response that they were all general lepidopterous parasites he 

 suggested the sending of the surplus to Massachusetts for use 

 against the Gypsy moth. Mr. Fernow mentioned an outbreak 

 of Orgyia pudibunda nearly 20 years ago upon the Island of 

 Ruegen in the Baltic Sea. The government expended large 

 sums of money for two years in collecting and burning cocoons. 

 One day, however, the overseer of this work noticed parasites 

 issuing in numbers from the pile of cocoons which had been laid 

 aside for burning. After examination he gave orders that the 

 work be stopped, with the result that the insect was practically 

 non-existent the following year and a large sum of money was 

 saved. This brought up a general discussion on the work of 

 parasites. 



Dr. Lugger spoke of the occurrence in great numbers of a 

 Tortricid on box elder in Minnesota. He had made his prepa 

 rations for spraying, but before beginning the operation an ex 

 amination showed the occurrence of parasites in force. He, 

 therefore, did not spray and the To x rtricid was reduced by its 

 parasites to innoxious numbers. Mr. Swingle referred to a case 

 in which he had sprayed with Bordeaux mixture in Florida, 



