592 



INSECTA. 



Q 



thorax (stalked). In the female sex the abdomen ends with an 

 ovipositor (terebra), which as a rule is retracted, or with a poison 

 spine (aculeus). The latter develops from six warts, of which four 

 belong to the ventral side of the penultimate, two to that of the 

 antepenultimate segment. The sting (fig. 487) consists of the 

 grooved piece (sting-groove), two piercing stylets and two sting- 

 sheaths (with oblong plates) and is retracted when at rest. The 

 grooved piece, the furrow of which is directed downwards, arises 

 from the inner pair of warts of the penultimate segment, while the 



piercing stylets on the 

 edge of the grooved piece 

 correspond to the pair of 

 warts of the antepenulti- 

 mate segment. Finally 

 the segments also take 

 part in the formation of 

 this apparatus, inas- 

 much as they furnish 

 powerful supporting 

 plates for the sting 

 (quadratic plate and 

 angular piece). 



The nervous system 

 consists of a large com- 

 plicated brain, an in- 

 fra- O3sophageal ga iiglion , 

 two thoracic ganglia 

 (the ganglia of the 

 mesothorax and meta- 

 thorax are fused with 

 the anterior abdominal 

 ganglion), and five to 

 six euusflia. in the ab- 



PIG. 487. Stinging apparatus of the honey bee from 

 the dorsal side (after Kraepelin). GD, poison gland ; 

 Gb, poison reservoir ; 7>, gland; Sfr, grooved piece with 

 the two stylets ; Ba, swollen base of the grooved piece ; 

 JB, curved root of the same ; W, angular piece ; Sh, 

 sheath of spine ; O, oblong plate ; Q, quadratic plate ; 

 Stl', Stlj", the two piercing spines on the ventral side 

 of the grooved piece. 



domen. 



The alimentary canal frequently attains to a considerable length, 

 especially in those Hymenoptera which with a longer life cumber 

 themselves with the care and nourishment of the young. Large 

 salivary glands are present. The narrow (esophagus usually dilates 

 to a suctorial stomach, more rarely to a spherical gizzard (ants). A 

 considerable number of short Malpighian tubules open into the 

 intestine (hindgut). 



