4 6 



Poisonous Arthropods 



32 The poisonous saddle back caterpillar. Empreti 

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



(fig. 32), is another which possesses 

 belongs to the group of Eucleidse, or 

 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 



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 



nettling hairs. This species 



slug caterpillars. It can be 



33o. lo moth larvae on willow. Photograph by M.V. S. 



