AN INTRODUCTION TO ENTOMOLOGY. 



The Mouth-parts. 



The mouth-parts (Fig. 22) consist typically of an upper lip, labnnn 

 (8), an under lip, labiion (12), and two 

 ' MIL; hori/nntally between 

 them. The upper pair of jau-, are called 

 the jnamiib: the lower pair, the 



ina * llllC ( I! )' Ihc ma - xill;l> -"Hi labium 

 are each furnished with a pair of feelers. 

 called respectively the Maxillary palpi 

 (lit/), and the labial palpi i i 2d . There 

 may be also within the mouth one or two 

 tongue-like organs, the cpipharynx (9) and 

 hypopharynx (^13). 



No set of organs in the body of an insect 

 vary in form to a greater degree than do the 

 F,c. "-MoutMr" of the Red- mouth . parts . Thus wilh S(>mc lhe n)()Uth 



formed for biting, while with others it is : 

 for sucking. Among the biting insects some are predaceous, and li 



1 for seizing and tearing their prey ; others feed upon vegetable matter, 

 and have jaws for chewing this kind of food. Among the surkir. 

 the butterfly merely sips the nectar from flowers, while the mosquito needs a 

 powerful instrument for piercing its victim. In this chapter the typical 

 of the mouth-parts as illustrated by the biting insects is described. The 

 i- modifications of it presented by the sucking insects are described later, 

 in the discussions of the characters of those insects.* 



The Ldbrum. The labrum or upper lip (8) is an appendage of the cephalic 

 margin of the dorsal part of the head. It is usually a narrow transverse sclerite. 

 inserts it is large and projecting, and often notched; in others it is 

 concealed beneath a largely developed clypeus. 



The MilmUbUs.1\iK. mandibles (10) are the dorsal pair of jaws. They vary 

 much in form, but are usually three-sided, with their lateral + surface more or 



* The more important papers on the nomenclature of tin- parts of the mouth in biting 

 insects are the following: 



KIRHY A Introduction to Entomology, vol. III. .(1818.) 



MACLEAY, W. S. Horae entomologicat (2 vols., 1819, 1821). This work I h. 

 seen. 



STRAUS-DURCKHKiM. II . E. Considerations i^'m'-rale sur 1'anatomic cli-s animaux 

 articules. (1828.) 



\ki) A paper on the nomenclature of the parts of tin- head of i 



(1834.) 



NEWPORT, G. The article " Insecta," Todd's Cycl. of Anat. and Physio). (1839.) 



\. Recherches sur Ics transformations des appendices dans ]< 

 Annales des Sciences Naturellcs, t. II. (1844.) 



t I have not attempted to determine the normal position of the mouth-parts, l.m have 

 described each with its distal end directed cephalad. This seems to m< th< 

 likely to lead to confusion. 



