1907.] PUBLIC DOCUMENT- -No. 73. 155 



So much has been written concerning the brown-tail moth (Euproctis 

 chrysorrho&a) that it is unnecessary to review its life history and habits 

 in this paper. Full information on these points, together with an ac- 

 count of the introduction of the moth into this country and its subse- 

 quent multiplication, is given in the report of Fernald and Kirkland 



(TV 



In June, 1901, Dr. J. C. White (17), in a letter to the editor of the 

 Boston " Medical and Surgical Journal," called attention to a peculiar 

 type of dermatitis, which he thought was undoubtedly due to the cater- 

 pillar of the brown-tail moth. The dermatitis, which was urticarial in 

 character, usually occurred on the neck, although the face and hands 

 were sometimes affected. All patients afflicted gave history of the re- 

 moval of a caterpillar from the parts affected just prior to the appear- 

 ance of the eruption. Soon after this, Dr. E. R. Meek (11), likewise 

 in a letter to the editor of the Boston " Medical and Surgical Journal," 

 ascribed the dermatitis to the hairs of this caterpillar, since these ele- 

 ments are very brittle and easily detached. Fernald and Kirkland, in 

 the report already referred to, state that the irritation is produced only 

 by certain short barbed hairs, which they term " nettling hairs," and by 

 no others. 



The irritating properties of species closely allied to the brown-tail 

 moth have long been known to European entomologists. There is in 

 the London " Entomologist " a series of notes recording the observa- 

 tions of a number of entomologists who have experienced irritation of 

 the skin after handling specimens of these closely allied species. In the 

 year 1865, South (14), after collecting specimens of Porthesia similis, 

 experienced intense itching, urticaria about the neck and edema of the 

 eyelids, but did not at that time ascribe the condition to the handling 

 of the moths. Kendall (13) found that the cocoons as well as the larvae 

 of the moth may produce irritation. Anderson (1) found that handling 

 the imagoes of Liparis auriflua, another species closely allied to the 

 brown-tail, was. followed by urticaria. He further states that merely 

 to walk, during a breeze, by certain hedges infested by this species is 

 sufficient to produce the rash. Swinton (15) held the opinion that the 

 hairs of the caterpillars are coated with a poisonous substance, which 

 exudes from the scarlet warts on the hinder segments. The fact that 

 cocoons, empty and exposed to the weather for months, are still capable 

 of producing the rash, seemed to Cockerell (5) and others to militate 

 strongly against the theory that the effects are caused otherwise than 

 by the mechanical action of the hairs. 



An interesting series of experimental inoculations is furnished by 

 Carter (3). He inoculated his own skin with various species, with the 

 following results: Porthesia similis produced redness, itching, pimples, 



!The figures enclosed in parentheses refer to the list of reference works appended 

 to this article. 



