NARRATIVE OF PROGRESS OF WORK. 65 



the writer had been unable to secure answers to letters addressed 

 to correspondents in Russia and the reported unsettled condition 

 of affairs in that country deterred him during the 1905 and 1906 

 trips from visiting the Russian southern Provinces. In the late 

 summer of 1906, however, advices were received from Prof. J. Por- 

 chinsky, of the ministry of agriculture at St. Petersburg, with the 

 information that in the southern part of. Russia both the gipsy moth 

 and the brown-tail moth were at that time occurring in sufficiently 

 great numbers to enable the collection of parasites and commending 

 the writer to certain officials, trained entomologists, in Simferopol 

 (Crimea), Kishenef (Bessarabia), and Kief. Prof. Porchinsky wrote 

 that he had apprised these officials of the intended visit, and plans 

 were therefore made to include southern Russia in the itinerary for 

 the spring of 1907. 



During the autumn of 1906 egg masses of the gipsy moth con- 

 tinued to be received from parts of Europe, and during the winter 

 hibernating nests of the brown-tail moth were sent in. More than 

 111,000 nests were received from different portions of the European 

 range of the species. These were placed in the especially constructed 

 cages, and from many of them large numbers of parasites were 

 reared, issuing mainly during the month of May, 1907. As it hap- 

 pened, the month of May in New England, as well as in other parts 

 of the United States, was phenomenally cold and wet. As a result 

 of this unlooked-for condition very many of the parasites refused 

 to leave the nests until they were so weakened as to be unable to 

 survive the close confinement and careful scrutiny to which they 

 were necessarily subjected in order to ehminate the danger of intro- 

 ducing secondary parasites. As a result, a smaller number of Ptero- 

 malus egregius was colonized in t,he summer of 1906, but 40,000 speci- 

 mens were put out in several localities, the principal colonies consist- 

 ing, respectively, of 13,000, 11,000, and 7,000 individuals. At this 

 time, as well as in the summer of 1906, although this fact has not as 

 yet been stated, a number of important parasites of the genus Mono- 

 dontomerus issued from the winter nests and were allowed to escape. 

 As will be shown subsequently, this parasite has proved to be more 

 important than the Pteromalus and has made a phenomenal spread. 

 *In this important work with the introduced hibernation nests 

 of the brown-tail moth it was early found most difficult to preserve 

 the health of the laboratory assistants. The irritating and poisonous 

 hairs of the brown-tail moth larvae, of which the nests are full, soon 

 penetrated the skin of the assistants handling them, entered their 

 eyes and throats, and the atmosphere of the laboratory became 

 almost filled with them. It was necessary that the rooms should 

 be kept thoroughly closed; double windows and screens were used, 

 62188°— Bull. 91—12 5 



