ANATOMY OF INSECTS- -EXTERNAL 19 



around the greatly elongated tongue (hypopharynx) which is used 

 for lapping and sucking, though the mandibles are still functional 

 and are used in shaping wax and pollen. 



It should be noted that in several of these orders having suctorial 

 mouth-parts in the adult stage the larvae have true biting mouth- 

 parts. Caterpillars of all the Lepidoptera and the larvae of many 



f 



FIG. 21. Mouth-parts of the honey-bee 



, antenna ; /, labellum ; ^, glossa, or tongue ; /;, labrum ; Ip, labial palpi ; m, mandible ; 

 mx, maxilla ; ;/z.t/, maxillary palpus ; pg, paraglossa 



families of flies and Hymenoptera have biting mouth-parts and are 

 injurious to vegetation, while the adults may be entirely harmless. 

 This difference in the mouth-parts of the same insect in different 

 stages must be borne in mind in considering insecticides for them. 



