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THE BOOK OF NATURE STUDY 



Within the terminal segments of the abdomen are hidden, two 

 in the male and three in the female, other segments greatly 

 modified in shape, and forming the reproductive clasping 

 apparatus of the male, and the sting and its accessories in the 

 female. 



Sting. The sting consists of three long pieces, which can 

 be thrust out from the end of the abdomen by means of a com- 



LN 



NP 



FIG. 74. Sting apparatus of wasp, and (below) tip of one needle, showing poison 

 channel and its outlets through the bases of the barbs. D, director ; E, in-turned 

 edges of director ; GH, GH', guiding hairs of left and right sides ; GS, guiding 

 studs inside D ; LD, lever of left side for extension of D ; LN, LN', levers for 

 extension of right and left needles ; N', N, beyond tip of D ; N, right needle with- 

 drawn from D ; NP, NP', enlargements on needles : (?) pistons for sweeping 

 poison onwards. 



plicated set of levers and muscles lodged within. The largest 

 of these three is the part that can be seen darted out when a 

 wasp attempts to sting ; it is a hollow, sharply pointed organ, 

 the cavity being open ventrally along the broader anterior region 

 and also at the point. Within it lie two three-sided, bayonet- 

 shaped " needles " bearing six barb-hooks at their apices. These 

 needles are the true stinging organs, the larger outer structure, 

 though capable of piercing the skin, serves chiefly to ensheathe, 



