CHAP. IV.] 



MEANS OF DEFENCE IN INSECTS. 



43 



at a safe distance from the vulnerable parts of the body. In other 

 cases special groups of hairs may be modified into defensive 

 weapons — tussocks, spines, stinging hairs, etc. A brown caterpillar 

 (Taragama siva) found commonly on babul (Acacia arabica) is clothed 

 With short hairs and bears just behind the head two large patches 

 of short black hairs which, when annoyed, it brings into contacl 



Taragama si tnink. 



; an original photograph l>y C. Narayana Ayyar.) 



with the disturber by lashing about with the lore part of it-- body, 

 the short hairs readily penetrating and becoming detached in the 

 human skin. This is a common method of defence in this family 

 (Lasiocampidce) and the larval hairs are often woven into the cocoon 

 from which they project on end to form a veritable "cheveux-de- 

 frise." Sometimes, particularly in the slug-like caterpillars of the 

 Limacodidae, the hairs may be modified to form stinging organs 

 which can inflict very severe punishment on an aggressor. 



The production of sound is another mode of defence in insects, 

 many of which stridulate when picked up. Some Cicadas, when 

 caught, will utter a piercing shriek very different in tone from 



