26 FIELD WORK AGAINST GIPSY AND BROWN-TAIL MOTHS. 



Underclothes and bedding should not be put out upon the line 

 during the caterpillar season, as the floating hairs may alight on such 

 articles, which, when used, may result in serious poisoning. 



During the year 1906 a careful study of this dermatitis was made 

 by Dr. E. E. Tyzzer, of the Harvard Medical School, and a report 

 was published by him.*^ 



He concludes from his investigation that the barbed hairs not only 

 cause a mechanical irritation but that they contain a poison which 

 acts directly on the corpuscles of the blood. This results in a break- 

 ing down of the corpuscles to a certain extent and in their assuming 

 a jagged outline instead of a circular one. 



Such a multitude of people have suffered from this form of poison- 

 ing that many remedies have been prepared and sold which are 

 warranted to give relief. During the summer metropolitan news- 

 papers and many of the smaller papers in New England contain 

 advertisements of remedies for the brown-tail rash. The trouble is 

 more serious during hot weather, when persons are perspiring freely, 

 and the skin at this time seems less resistant to the entrance of the 

 spines. 



Some of the advertised remedies give a certain measure of relief, 

 but none of the remedies suggested is wholly efhcacious. Applica- 

 tions which are cooling to the skin, such as witch-hazel or alcohol, 

 serve to allay the irritation to some extent and reduce the suffering 

 caused by the poison. 



The internal irritation which is caused by breathing or swallowing 

 the poisonous hairs is often very serious and no effective remedy has 

 been found. 



NATURAL ENEMIES OF THE GIPSY AND BROWN-TAIL MOTHS 

 NATIVE TO AMERICA. 



Aside from the experimental work on insecticides and a careful, 

 detailed study of all phases of the life history and habits of the gipsy 

 and brown-tail moths, considerable time was devoted by the Massa- 

 chusetts authorities to an investigation of the native natural enemies 

 which attack them in the field. 



Both species are partially controlled in Europe by parasites and 

 predaceous enemies, and it was desirable to ascertain if the closely 

 related beneficial species in this country were showing any marked 

 tendency toward controlling the pests. 



Field observations on birds were made by Mr. Forbush, who was 

 ably assisted in this work by Messrs. J. A. Farley and F. H. Mosher, 

 the late Charles E. Bailey, and numerous other careful observers. 

 A large number of native insectivorous birds were found feeding on 



o In Second Annual Report of the Superintendent for Suppressing the Gypsy and 

 the Brown-tail Moths, Boston, 1907, pp. 154-168. 



