ON THE URTICATING HAIRS OF SOME LEPIDOPTERA. 5 



of those larvae, and the exertion caused perspiration. After 

 passing my hand across my perspiring brow, I had a repetition 

 of the similis attack, but in a much milder form. Since then I 

 have, nearly every season, taken up odd larvae of Bomhyx 

 quercus, B. ruhi, and Odonestis potatoria, and in every case have 

 noticed that the tips of my fingers and thumb were thickly 

 " felted " with the hairs of the larva handled. Since my B. ruhi 

 experience I have always been studiously careful not to touch my 

 face or neck. At the same time, when my hands have been hot 

 I have frequently found a slight itching between the fingers, but 

 the hairs sticking into the thicker skin of the thumb and fingers, 

 did not cause any itching in those parts. 



Mr. Swinton, in ' Notes on the Urticating Property of the 

 Hairs of the Larvae of Liparis auriflua [Porthesia similis),' 

 communicated to the Entomological Society of London, August 

 6th, 1879, expresses his opinion that the hairs of the larva are 

 covered with a poisonous liquid, exuded from the scarlet warts on 

 the hinder segments. This is the only suggestion I can find as 

 to the probable cause of the intense irritation set up by the hairs 

 of the larva of this species. Assuming Mr. Swinton to be right 

 with regard to the hairs of the larva, what about the hairs of the 

 imago ? Are these also coated with a poisonous liquid ? 



The hairs of larvae of the genus Cnethocampa are barbed 

 (one species of the genus, pityocampa, was reported as occurring in 

 Kent, in 1873-4), and possess great urticating power. The 

 hairs of the larva are perhaps the most virulent, but the hairs of 

 the imago, and even the dust of the web, are capable of causing 

 great irritation. It may be supposed that the greater irritation 

 of the larval hairs as compared with those of the imago or the 

 dust from the nest, is due to their barbed points. Especially 

 would this appear to be the case if, as I have been informed, 

 irritation in its severest form is apt to return at intervals for 

 years after contact with the hairs of the larva. 



Whether irritant poisons are or are not introduced with the 

 hairs, may afford matter for discussion ; but it does not appear 

 altogether unreasonable to suppose that the hairs in themselves — 

 especially barbed hairs — are quite capable of producing a 

 considerable amount of discomfort, if not absolute pain, when 

 introduced liberally into the human skin. 



That pain is, sometimes at least, due to other than mere 



