134 WASPS [CH. V 



more of the wing is cut off the volume of the sound 

 decreases but the note rises in pitch. 



There is no doubt that the buzzing produced by many 

 insects has a protective value in warning insectivorous 

 foes of dangerous attributes. Lizards and frogs which 

 have once had experience of the sting of a bee exhibit 

 serious alarm at the loud buzz of the harmless mimic 

 Eristalis tenax, the drone fly. I have noticed that the 

 sand-wasp, Ammophila hirsuta, emits a loud and angry 

 buzz while underground engaged in excavating her 

 burrow, and have observed would-be inquiline Diptera 

 and Hymenoptera start away from the hole and retreat 

 hastily on hearing the sound emerge from the ground. , 



The functions of the legs, digestive, circulatory, respi- 

 ratory, nervous and excretory systems of the wasp do 

 not greatly differ from those of the cockroach described 

 in an earlier chapter. We will therefore pass on to 

 consider that most distinctive appendage of the higher 

 Hymenoptera, the sting. Strictly this organ belongs to 

 the female reproductive system and corresponds to an 

 ovipositor. It has however been withdrawn into the body 

 and lost all direct connexion with oviposition, the eggs 

 no longer passing through it but escaping at its base. 

 Its existing function is that of a weapon of defence and 

 offence. The males are of course destitute of a sting. 

 The sting 1 itself consists of three long pieces, a larger 

 dorsal "director" (D) (usually mistaken for the sting itself) 



] Cf. Kraepelin, Zeit. iviss. Zool. xxm. 1873. Carlet, Bull. Soc. Ent. 

 Fr. (b) iv. 1884 and C. R. Acad. Sci. Paris, xcix. 1884. Dewitz (Bee), 

 Zeit. wiss. Zool. xxv. 1875. (Ant) ibid. xxvn. 1877. 



