The Puss Caterpillar, 



11 



be done to eliminate the pest, and the street trees were sprayed with 

 arsenicals on an extensive scale. 



It has been found that the long hairs on the caterpillars are harm- 

 less, but the shorter spines which are hidden among them are respon- 

 sible for the ill effects. Most of the stings are caused by inadver- 

 tently pressing one of the caterpillars against an exposed part of the 

 body. The severity of the sting seems to depend upon the tender- 

 ness of the place struck and also the amount of pressure applied. 

 As has been stated, the severity of the reactions varies much with 

 the person. 



Almost immediately after any portion of the body comes in contact 

 with one of these caterpillars an intense burning pain is felt, described 

 by some as similar to a severe nettle sting. This usually becomes worse 

 accompanied by itching for several minutes and persists from 1 to 12 

 hours and sometimes longer. Almost immediately after a sting 

 the area touched by the caterpil- 

 lar shows minute raised whitish 

 spots or papules which soon become 

 red, followed by spreading of the 

 inflammatory area for several inches 

 and often accompanied by gen- 

 eral swelling of the portion of the 

 body stung. Stings on the wrist 

 have been followed by a swelling 

 of the entire arm to almost double 

 its normal size. A feeling of numb- 

 ness which almost assumes the 

 characteristics of paralysis accom- 

 panies the swelling. This is usually 

 confined to the member attacked 

 but may be generalized. Appar- 

 ently stings on the neck are even 

 worse, as the writer has one record 

 of a man who was stung severely 

 on the neck and completely incapa- 

 citated, being confiiied to the hos- 

 pital for six days. These paralytic 

 symptoms are often accompanied by 

 nausea and sometimes by vomiting. The stings are especially severe 

 among young children, who often develop considerable fever and nerv- 

 ous sjmptoms. These sometimes last for a day or two and are accom- 

 panied by nausea, especially during the first few hours. Usually with- 

 in two or three hours after a sting, the reddened pimple-like swellings 

 at the site assume the appearance of small vesicles or blisters. These 

 usually persist for a few hours and then apparently harden through 

 absorption, leaving a roughened area. In some instances the 

 discoloration of the skin surrounding the point of attack is rather 

 marked, varying from a deep red to almost black. The paralytic 

 s^Tnptoms usually subside vdih. the pain, but the local lesions often 

 persist for several days. 



While it is certain that the spines are the direct cause of the net- 

 tling, it is rather difficult to explain the very severe symptoms. 



Fig. 



-Ventral view of pupa of puss 

 caterpillar. 



