524 



ISSECTA* 



tern, fig. 430). While the labium is usually reduced to a simple 

 plate with two lateral palps (palpi labiales), in the Orlhojttera we can 

 distinguish a proximal piece (submentum), fixed to the throat, from 

 a second piece, bearing the two palps (mentum), at the point of 

 which there is a piece, the tongue (glossa) (fig. 430, e, L. in), 

 and sometimes secondary pieces, the paraylossce, (L. ex). The sub- 

 mentum evidently corresponds to the fused basal joints (cardo), 

 the mentum to the fused shafts (stipes), the simple or bifid glossa 

 to the lobus interims, and the paraglossse to the lobus externus of the 

 first maxill?e. Median projections on the internal surface of the 

 upper and lower lips are distinguished as epipkarynx and liypo- 



pliarynx respectively. 



The above description refers to insects 

 which gnaw or bite their food. When the 

 food is fluid, the mouth parts, either in 

 whole or part, become so remarkably modi- 

 fied that it required the penetration of 

 Savigny to establish their morphological 

 relations. The biting mouth parts found 

 in the orders of the Coleoptera, the 

 Neuroptera and the Orthoptera are most 

 nearly allied to the mouth parts of the 

 Hym&noptera, which may be described as 

 a licking apparatus (fig. 431). The upper 

 lip and mandibles agree with tho.se of the 

 biting apparatus, but the maxillae and la- 

 bium are more or less elongated and modi- 

 fied, to admit of licking and sucking up 

 fluids. 



Mouth parts adapted for sucking are 

 found in the Lepidoptera, where the first 

 maxillae are united to form a sucking tube, 

 while the other parts are more or less 

 aborted (fig. 432). Finally the piercing mouth parts of the 

 Diptera and Rhynchota also possess a sucking apparatus, which is 

 usually formed of the labium ; but there are also styliform wea- 

 pons, by means of which access is gained to the nourishing fluid, 

 which is to be sucked up (figs. 433, 434). Tlicsi- weapons may be 

 formed by the mandibles, and also by the maxilla;, and even the 

 hypopharynx and epipharynx may be used, undergoing numerous 

 modifications. Since the piercing part of the apparatus may be 



Fio. 431. Mouui parts of 

 Aiithophora reliixa (after 

 Newport) A, Antennae; 

 Oc, ocelli ; MJ, mandibles ; 

 Mi, maxilla?; Mxf, max- 

 illary palp ; U, labial 

 palp ; Gl, glossa ; Pg, 

 paraglossa 1 . 



