1908.] PUBLIC DOCUMENT- -No. 73. 175 



mond Mokshetsky, director of the Museum of Natural History at that 

 place. Professor Mokshetsky is a trained economic entomologist, well 

 informed upon all American methods, and in the most courteous way 

 volunteered his energetic assistance without compensation. From him 

 also has been received during- the summer important material. Re- 

 turning by the way of Constantinople (where it was found impossible 

 to secure assistance) to Vienna, later proceeding from Vienna to various 

 points, including Dresden, Halle a. S., Berlin, Eberswalde and Zurich to 

 Paris, I was able to give additional instructions to Fritz Wagner in 

 Vienna, E. Schopfer in Dresden, Miss Marie Riihl at Zurich, and to 

 engage the active co-operation of Dr. M. Holrung at Halle a. S., Dr. R. 

 Heymons in Berlin, Dr. Carl Eckstein at Eberswalde and Prof. A. 

 Severin at Brussels. To each of these gentlemen I am greatly indebted 

 for courtesies and advice, as well as active assistance. On the return 

 trip to France I arranged with Mr. Rene Oberthiir of Rennes for a 

 regular station at Rennes, in charge of Prof. C. Houlbert of the Uni- 

 versity of Rennes, which will be in charge of an especial assistant 

 chosen by Professor Houlbert. In this especial work I was assured of 

 the good will and co-operation of the University of Paris by Prof. 

 Alfred Giard. 



As a result of this trip, much more material was received at the 

 North Saugus laboratory than ever before, so much, in fact, as to 

 demand a great extension of laboratory space. Especial efforts were 

 made to arrange for the importation of larger numbers of the egg- 

 parasites of both species, and to introduce in living condition the 

 important parasites of the genus Apanteles, which, according to my 

 field observations in Europe, are among the most important of the 

 European enemies of the gypsy moth. Previous importations of these 

 parasites had failed, owing to the fact that the adults emerged and 

 died on the journey. The present year, however, specific directions were 

 given to agents to send in young larvae of the second stage, and by this 

 means living specimens of the parasites in considerable numbers have 

 been reared at North Saugus. These, on issuing, laid their eggs in the 

 gypsy moth larvae in their first stage, and from these were secured the 

 cocoons and adults of a second generation, which was reared through 

 all of its stages on American soil. It is hoped to repeat this experience 

 on a more extensive scale next year, and thus to secure a very large 

 number of the adult parasites for colonization. 



An important result of this year's work has been a successful experi- 

 ment in rearing from the imported brown-tail moth nests of a very 

 large number of caterpillars which gave out in their later growth a 

 second lot of parasites entii'ely different from those reared in May from 

 the very young hibernating larvae. Last year, after the May parasites 

 had issued, the brown-tail larvae were destroyed. Among the later 

 parasites were at least two species of the genus Apanteles. 



Another important result of the work of the early summer was the 



