ANTENNATA MOUTH PARTS 



451 



The mechanism for sucking and stinging, which is occasionally very complicated, 

 and to which certain adaptations in the oesophagus (pumps, " fish trap " apparatus, 

 etc. ), belong, cannot be here more exactly described. 



The mouth parts of the other Hexapoda must be referred to one or other of the 

 types depicted. 



The mouth parts of the Coleoptera are for biting and masticating, similar to those 

 of the Orthoptera ; the masticatory ridges of the anterior maxillae are rarely trans- 

 formed into a sucking tube. 



The mouth parts of the Dermaptera, Epheineridce, Odonata, Plecoptera Corrodentia, 



FIG. 311. Mouth parts of the Hemiptera. A, of Pentatoma. B, of Pyrrhocoris. 



as before. 



Lettering 



Neuroptera, and Panorpata are also adapted for biting, and belong with various 

 deviations to the type of those of the Orthoptera and Coleoptera. 



The mouth parts of the Thysanoptera (Physopoda) hold a position intermediate 

 between the biting mouth parts of the Orthoptera and the sucking mouth parts of 

 the Rhynchota. The mandibles are changed into piercing setae, and come to lie 

 within a short tubular proboscis, which arises by the growing together of the upper 

 lip with the anterior maxillae and the lower lip (posterior maxillae). The 2 pairs 

 of maxillae have distinct palps and otherwise generally show the typical parts 

 variously modified. In the Trichoptera the mandibles are rudimentary, the 2 

 pairs of maxillae together form a sort of proboscis (for piercing and sucking), the 4 

 palps remaining separate on it. The palps, however, as well as the proboscis itself, 

 may disappear. 



In the Aphaniptera (Fleas) the mouth parts are for piercing and sucking. The 

 mandibles are toothed ridges which, together with the upper lip form the sucking 



