46 



Poisonous Arthropods 



■.vm-^yfnryu-. 



32 The poisonous saddle back caterpillar. Empretia 

 (Sibine) stimulea. Photograph by M. V. S. 



these long hairs are numer- 

 ous short spines connected 

 with underlying hypoder- 

 mal poison glands. These 

 hairs are capable of pro- 

 ducing a marked nettling 

 effect when they come in 

 contact with the skin. 

 This species is found in 

 our Atlantic and Southern 

 States. Satisfactory 

 studies of its poisonous 

 hairs and their glands have 

 not yet been made. 



Sibine stimulea {Em- 

 pretia stimulea), or the 

 saddle-back caterpillar 



(fig. 32), is another which possesses nettling hairs. This species 



belongs to the group of Eucleidse, or slug caterpillars. It can be 



readily recognized 



by its flattened 



form, lateral , brist- 

 ling spines and by 



the large green 



patch on the back 



resembling a 



saddle-cloth, while 



the saddle is repre- 

 sented by an oval, 



purplish-brown 



spot. The small 



spines are veno- 

 mous and affect 



some persons very 



painfully. The 



larva feeds on the 



leaves of a large 



variety of forest 



trees and also on 



cherry, plum, and 33o. lo moth larvse on willow. Photograph by M.V. S. 



