BROWN-TAIL MOTH AND PARASITES IN EUROPE. 133 



tory, they have received as much and as careful consideration as 

 have the parasites of the more dangerous pests. 



So far as known the brown-tail moth does not occur in Japan, and 

 in consequence no determined efforts have been made to secure, from 

 Japanese sources, parasites likely to attack it. It has an ally and con- 

 gener there in Euproctis conspersa Butl., which is attacked by a variety 

 of parasites, some of which may be expected to attack the brown-tail 

 moth if given an opportunity. A few of them have been collected 

 and forwarded to the laboratory through the great kindness of Mr. 

 Kuwana, but unfortunately have arrived in such condition, or at such 

 time of the year, as to make their colonization impossiJ)le. It is 

 intended in the near if not in the immediate future to devote some 

 time to the investigation of the Japanese parasites likely to be of 

 service in this respect, and, if any can be found of promise, to attempt 

 their importation into America. 



In Europe the brown-tail moth appears to be the more common of 

 the two insects under consideration and, taken all in all, it is probably 

 the more injurious as well. Neither in Europe nor in America does 

 it bring about the wholesale defoliation characteristic of an invasion 

 of the gipsy moth, but its injury is of a more insidious character and 

 more evenly distributed throughout the years. In Russia, in the fall 

 of 1910, the junior author was astounded at the tremendous abun- 

 dance of its nests in many localities, notably on the irregular hedge- 

 rows planted as a windbreak alongside the railroad in the midst of an 

 otherwise open prairie. Occasionally small scrubs of Crataegus, or 

 wild pear, completely isolated by what seemed to be miles of open 

 prairie, would be fairly covered with the nests. 



In gardens in the vicinity of Kief pear and apple trees were fre- 

 quently injured to a considerable extent by its caterpillars, and some- 

 times to a greater extent by the caterpillars of Aporia cratsegi L., 

 which are similar in their habit, and were constructing their own hiber- 

 nating nests side by side with those of the brown-tail moth. In the 

 forests round about it was common, but except occasionally not quite 

 so common as in southeastern New England. On one occasion in 

 excess of 50 nests were noted upon a small hawthorn which stood at 

 the edge of an oak forest. This was just a little worse than anything 

 which has been seen in America. 



In southern France the circumstances under which it occurred were 

 as surprising as those under which the gipsy moth was encountered, 

 in respect to their departure from that which past experience led the 

 visitor to consider as the normal. M. Dillon, who had collected and 

 forwarded to the laboratory a considerable quantity of the winter 

 nests, undertook to guide the visitor to the locality where they were 

 collected. The way led through a rich and fertile valley, with many 

 sorts of trees, including apple and pear, as well as hawthorn and oak, 



